\relax
-\@writefile{toc}{\contentsline {section}{\numberline {.2}Overview}{41}{section..2}}
-\@writefile{toc}{\contentsline {section}{\numberline {.3}Microprocessor}{41}{section..3}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4}{\ignorespaces AVR Butterfly\relax }}{42}{figure..4}}
-\newlabel{avr_butterfly.pdf}{{4}{42}{AVR Butterfly\relax \relax }{figure..4}{}}
-\@writefile{lof}{\contentsline {figure}{\numberline {5}{\ignorespaces ADC4,6,7 Input\relax }}{42}{figure..5}}
-\newlabel{adc_normal.pdf}{{5}{42}{ADC4,6,7 Input\relax \relax }{figure..5}{}}
-\@writefile{lof}{\contentsline {figure}{\numberline {6}{\ignorespaces Differential Input stage for ADC5\relax }}{44}{figure..6}}
-\newlabel{adc5.pdf}{{6}{44}{Differential Input stage for ADC5\relax \relax }{figure..6}{}}
-\@writefile{lof}{\contentsline {figure}{\numberline {7}{\ignorespaces Logic Power Supply\relax }}{45}{figure..7}}
-\newlabel{logic_ps.pdf}{{7}{45}{Logic Power Supply\relax \relax }{figure..7}{}}
+\@writefile{toc}{\contentsline {section}{\numberline {A.4}Data Aquisition Hardware}{47}{section.A.4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {A.4.1}Overview}{47}{subsection.A.4.1}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {A.4.2}Microprocessor}{47}{subsection.A.4.2}}
+\@writefile{lof}{\contentsline {figure}{\numberline {A.6}{\ignorespaces AVR Butterfly\relax }}{48}{figure.A.6}}
+\newlabel{avr_butterfly.pdf}{{A.6}{48}{AVR Butterfly\relax \relax }{figure.A.6}{}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {A.4.3}ADC Inputs}{48}{subsection.A.4.3}}
+\@writefile{lof}{\contentsline {figure}{\numberline {A.7}{\ignorespaces ADC4,6,7 Input\relax }}{48}{figure.A.7}}
+\newlabel{adc_normal.pdf}{{A.7}{48}{ADC4,6,7 Input\relax \relax }{figure.A.7}{}}
+\@writefile{toc}{\contentsline {subsubsection}{Differential ADC Input}{49}{section*.41}}
+\@writefile{lof}{\contentsline {figure}{\numberline {A.8}{\ignorespaces Differential Input stage for ADC5\relax }}{50}{figure.A.8}}
+\newlabel{adc5.pdf}{{A.8}{50}{Differential Input stage for ADC5\relax \relax }{figure.A.8}{}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {A.4.4}Temperature Measurement}{51}{subsection.A.4.4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {A.4.5}Power Supplies}{51}{subsection.A.4.5}}
+\@writefile{toc}{\contentsline {subsubsection}{Logic Power Supply}{51}{section*.42}}
+\@writefile{lof}{\contentsline {figure}{\numberline {A.9}{\ignorespaces Logic Power Supply\relax }}{51}{figure.A.9}}
+\newlabel{logic_ps.pdf}{{A.9}{51}{Logic Power Supply\relax \relax }{figure.A.9}{}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {A.4.6}DAC Output}{52}{subsection.A.4.6}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {A.4.7}RS-232 Communications}{52}{subsection.A.4.7}}
\@setckpt{appendices/data_aquisition}{
-\setcounter{page}{47}
+\setcounter{page}{53}
\setcounter{equation}{0}
\setcounter{enumi}{3}
\setcounter{enumii}{0}
\setcounter{enumiii}{0}
\setcounter{enumiv}{11}
-\setcounter{footnote}{0}
+\setcounter{footnote}{1}
\setcounter{mpfootnote}{0}
\setcounter{part}{0}
-\setcounter{chapter}{0}
-\setcounter{section}{3}
-\setcounter{subsection}{0}
+\setcounter{chapter}{1}
+\setcounter{section}{4}
+\setcounter{subsection}{7}
\setcounter{subsubsection}{0}
\setcounter{paragraph}{0}
\setcounter{subparagraph}{0}
-\setcounter{figure}{7}
+\setcounter{figure}{9}
\setcounter{table}{0}
\setcounter{ContinuedFloat}{0}
\setcounter{r@tfl@t}{0}
\setcounter{parentequation}{0}
-\setcounter{Item}{20}
-\setcounter{Hfootnote}{2}
+\setcounter{Item}{33}
+\setcounter{Hfootnote}{6}
\setcounter{float@type}{4}
\setcounter{theorem}{0}
\setcounter{example}{0}
-\setcounter{section@level}{1}
+\setcounter{section@level}{2}
}
-\chapter*{Appendix - Data Aquisition Hardware}
+\section{Data Aquisition Hardware}
-\section{Overview}
+{\bf NOTE:} This is slightly out of date, since when the 610B ammeter mysteriously broke, I just used ADC5 for everything. So I can probably leave out all the stuff about the differences between ADC5 and the other ADC's. Then again, it's the appendix. I can probably leave \emph{all} of it out.
+
+\subsection{Overview}
In order to automate TCS experiments, both Digital to Analogue and Analogue to Digital Convertors were required (DAC and ADC). To provide these, a custom DAC/ADC Box was designed and constructed. The box can be controlled by any conventional computer with available RS-232 serial communication (COM) ports. Most modern computers no longer feature COM ports; a commercially available convertor can be used to interface between the box's RS-232 output and a standard Universal Serial Bus (USB) port.
\item RS-232 communications for control by a conventional PC or laptop
\end{itemize}
-\section{Microprocessor}
+\subsection{Microprocessor}
The DAC/ADC box has been based upon Atmel's AVR Butterfly; an inexpensive and simple demonstration board for the ATMega169 16 Bit microprocessor. The features of the AVR Butterfly include easily accessible ports for Analogue to Digital Convertor (ADC) inputs and digital input/output, an onboard Universal Asynchronous Reciever/Transmitter (USART) for RS-232 serial communications, and a 6 character Liquid Crystal Display (LCD). The AVR Butterfly can be programmed using a conventional computer over the USART using a RS-232 COM port. For modern computers (which do not usually posess COM ports), a RS-232 to USB converter may be used.
Figure \ref{avr_butterfly.pdf} is a labelled photograph of the AVR Butterfly showing the use of the available ports for this project.
Unless otherwise stated, all voltage differences are specified relative to the power supply ground of the AVR Butterfly.
-\subsection*{ADC Inputs}
+\subsection{ADC Inputs}
The AVR Butterfly offers easy access to four of the ATMega169's ADCs through PORTF. Each ADC is capable of measuring voltages of $0 < V_{\text{adc}} < V_{cc}$ with 10 Bit resolution. For measuring voltages outside this range, some circuitry is required between the input voltage and the ADC input. In addition, it is desirable to provide the ADC with some form of input protection against accidental overloading. Figure \ref{adc_normal.pdf} shows the input circuit which was used for three of the four available ADCs.
V_{\text{in}} &= \left(\frac{\text{ADC counts}}{2^{10}}\right) \times \frac{R_1 + R_2}{R_1} V_{cc}
\end{align*}
-\subsubsection*{Differential ADC Input}
+\subsubsection{Differential ADC Input}
During the testing of the TCS experimental apparatus, it became desirable to measure the emission current of the electron gun. The electrometer used for this current measurement was capable of producing an analogue output in the range of $0-1V$. However, the negative terminal of this output was not at ground potential, but rather at the same terminal as the negative input terminal. Directly connecting the electrometer output to one of the ADC inputs discussed above would create a short circuit between the initial energy power supply, and ground (refer to Figures \ref{} and \ref{}). Therefore, it was decided to add a differential stage before the input of one of the ADCs.
The low pass filters were added to the inputs of ADC5 after it was found that an unacceptable level of AC noise was being output by the electrometer. The level of noise was too high to be filtered in software, for reasons that will be discussed in Appendix D.
-\subsection*{Temperature Measurement}
+\subsection{Temperature Measurement}
The AVR Butterfly features an onboard thermistor connected to ADC0. Reading ADC0 and applying the formula given in the AVR Butterfly User's Guide \cite{} results in a temperature measurement. This was useful in establishing a link between the changing chamber pressure and the temperature of the laboratory (see Appendix C).
-\subsection*{Power Supplies}
+\subsection{Power Supplies}
Due to the presence of both analogue and digital electronics in the DAC/ADC box, three seperate supply voltages were required:
\begin{enumerate}
\item Digital logic in the range $3 \to 4.5$V
Circuitry was designed which allowed two seperate single pole power supplies to be used for Digital logic and the op-amps. A dual 0-30V DC power supply has been used for both digital and analogue circuitry.
-\subsubsection*{Logic Power Supply}
+\subsubsection{Logic Power Supply}
The AVR Butterfly runs off $3V < V_{cc} < 4.5V$ DC. Since $V_{cc}$ was also used as the reference voltage for the ADCs and DAC output, it was desirable that $V_{cc}$ be kept constant, despite the absolute level of the power supply. A $3.3V$ voltage regulator has been used for this purpose. The capacitor further smooths the output by shorting high frequency fluctuations to ground.
When the DAC/ADC box was first constructed $V_{cc}$ was supplied by three $1.5V$ batteries. However, due to higher than expected power usage, and the unreliability of the voltage regulator as the input voltage fell below $4V$, inputs for an external power supply were later added.
The buffer amplifier ensures that negligable current can flow from the power supply into the logic and ADC circuits, whilst the capacitor removes high frequency fluctuations of the power supply relative to ground.
-\subsection*{DAC Output}
+\subsection{DAC Output}
A commercial DAC board was used to produce the DAC output. The Microchip MCP4922 ET-Mini DAC is controlled by the AVR Butterfly using Motorola's Serial Peripheral Interface (SPI) Bus. The software used to implement SPI between the MCP4922 and the AVR Butterfly is discussed in Appendix D.
The ET-Mini DAC can only be powered off $3V$ to $5V$. Using $V_{cc} = 3.3V$ means that the DAC output cannot exceed $V_{cc} = 3.3V$. For TCS, energies of up to $15eV$ are required, so amplification of the DAC output was clearly necessary. A simple non-inverting amplifier with a manually adjustable gain was used to amplify the DAC output by a factor of three. This output was then used to control a laboratory power supply to produce the full range of initial energies.
-\subsection*{RS-232 Communications}
+\subsection{RS-232 Communications}
The AVR Butterfly features an onboard USART, which can be used both for programming and communication with the ATMega169 processor. The RS-232 communications requires only three wires; Recieve (RX), Transmit (TX) and a common ground.
-\chapter*{Appendix - Data Aquisition Hardware}
+\section{Data Aquisition Hardware}
-\section{Overview}
+{\bf NOTE:} This is slightly out of date, since when the 610B ammeter mysteriously broke, I just used ADC5 for everything. So I can probably leave out all the stuff about the differences between ADC5 and the other ADC's.
+
+\subsection{Overview}
In order to automate TCS experiments, both Digital to Analogue and Analogue to Digital Convertors were required (DAC and ADC). To provide these, a custom DAC/ADC Box was designed and constructed. The box can be controlled by any conventional computer with available RS-232 serial communication (COM) ports. Most modern computers no longer feature COM ports; a commercially available convertor can be used to interface between the box's RS-232 output and a standard Universal Serial Bus (USB) port.
\item RS-232 communications for control by a conventional PC or laptop
\end{itemize}
-\section{Microprocessor}
+\subsection{Microprocessor}
The DAC/ADC box has been based upon Atmel's AVR Butterfly; an inexpensive and simple demonstration board for the ATMega169 16 Bit microprocessor. The features of the AVR Butterfly include easily accessible ports for Analogue to Digital Convertor (ADC) inputs and digital input/output, an onboard Universal Asynchronous Reciever/Transmitter (USART) for RS-232 serial communications, and a 6 character Liquid Crystal Display (LCD). The AVR Butterfly can be programmed using a conventional computer over the USART using a RS-232 COM port. For modern computers (which do not usually posess COM ports), a RS-232 to USB converter may be used.
Figure \ref{avr_butterfly.pdf} is a labelled photograph of the AVR Butterfly showing the use of the available ports for this project.
Unless otherwise stated, all voltage differences are specified relative to the power supply ground of the AVR Butterfly.
-\subsection*{ADC Inputs}
+\subsection{ADC Inputs}
The AVR Butterfly offers easy access to four of the ATMega169's ADCs through PORTF. Each ADC is capable of measuring voltages of $0 < V_{\text{adc}} < V_{cc}$ with 10 Bit resolution. For measuring voltages outside this range, some circuitry is required between the input voltage and the ADC input. In addition, it is desirable to provide the ADC with some form of input protection against accidental overloading. Figure \ref{adc_normal.pdf} shows the input circuit which was used for three of the four available ADCs.
V_{\text{in}} &= \left(\frac{\text{ADC counts}}{2^{10}}\right) \times \frac{R_1 + R_2}{R_1} V_{cc}
\end{align*}
-\subsubsection*{Differential ADC Input}
+\subsubsection{Differential ADC Input}
During the testing of the TCS experimental apparatus, it became desirable to measure the emission current of the electron gun. The electrometer used for this current measurement was capable of producing an analogue output in the range of $0-1V$. However, the negative terminal of this output was not at ground potential, but rather at the same terminal as the negative input terminal. Directly connecting the electrometer output to one of the ADC inputs discussed above would create a short circuit between the initial energy power supply, and ground (refer to Figures \ref{} and \ref{}). Therefore, it was decided to add a differential stage before the input of one of the ADCs.
The low pass filters were added to the inputs of ADC5 after it was found that an unacceptable level of AC noise was being output by the electrometer. The level of noise was too high to be filtered in software, for reasons that will be discussed in Appendix D.
-\subsection*{Temperature Measurement}
+\subsection{Temperature Measurement}
The AVR Butterfly features an onboard thermistor connected to ADC0. Reading ADC0 and applying the formula given in the AVR Butterfly User's Guide \cite{} results in a temperature measurement. This was useful in establishing a link between the changing chamber pressure and the temperature of the laboratory (see Appendix C).
-\subsection*{Power Supplies}
+\subsection{Power Supplies}
Due to the presence of both analogue and digital electronics in the DAC/ADC box, three seperate supply voltages were required:
\begin{enumerate}
\item Digital logic in the range $3 \to 4.5$V
Circuitry was designed which allowed two seperate single pole power supplies to be used for Digital logic and the op-amps. A dual 0-30V DC power supply has been used for both digital and analogue circuitry.
-\subsubsection*{Logic Power Supply}
+\subsubsection{Logic Power Supply}
The AVR Butterfly runs off $3V < V_{cc} < 4.5V$ DC. Since $V_{cc}$ was also used as the reference voltage for the ADCs and DAC output, it was desirable that $V_{cc}$ be kept constant, despite the absolute level of the power supply. A $3.3V$ voltage regulator has been used for this purpose. The capacitor further smooths the output by shorting high frequency fluctuations to ground.
When the DAC/ADC box was first constructed $V_{cc}$ was supplied by three $1.5V$ batteries. However, due to higher than expected power usage, and the unreliability of the voltage regulator as the input voltage fell below $4V$, inputs for an external power supply were later added.
\begin{center}
- \includegraphics[scale=0.70]{figures/logic_ps}
+ \includegraphics[scale=0.70]{figures/dac_adc_box/logic_ps}
\captionof{figure}{Logic Power Supply}
\label{logic_ps.pdf}
\end{center}
The buffer amplifier ensures that negligable current can flow from the power supply into the logic and ADC circuits, whilst the capacitor removes high frequency fluctuations of the power supply relative to ground.
-\subsection*{DAC Output}
+\subsection{DAC Output}
A commercial DAC board was used to produce the DAC output. The Microchip MCP4922 ET-Mini DAC is controlled by the AVR Butterfly using Motorola's Serial Peripheral Interface (SPI) Bus. The software used to implement SPI between the MCP4922 and the AVR Butterfly is discussed in Appendix D.
The ET-Mini DAC can only be powered off $3V$ to $5V$. Using $V_{cc} = 3.3V$ means that the DAC output cannot exceed $V_{cc} = 3.3V$. For TCS, energies of up to $15eV$ are required, so amplification of the DAC output was clearly necessary. A simple non-inverting amplifier with a manually adjustable gain was used to amplify the DAC output by a factor of three. This output was then used to control a laboratory power supply to produce the full range of initial energies.
-\subsection*{RS-232 Communications}
+\subsection{RS-232 Communications}
The AVR Butterfly features an onboard USART, which can be used both for programming and communication with the ATMega169 processor. The RS-232 communications requires only three wires; Recieve (RX), Transmit (TX) and a common ground.
\relax
-\@writefile{lof}{\contentsline {figure}{\numberline {5}{\ignorespaces Circuit Diagram for Electron Gun Control\relax }}{41}{figure..5}}
-\newlabel{electron_gun.pdf}{{5}{42}{Circuit Diagram for Electron Gun Control\relax \relax }{figure..5}{}}
-\@writefile{toc}{\contentsline {subsection}{\numberline {.1.1}The Ammeters}{42}{subsection..1.1}}
+\@writefile{toc}{\contentsline {section}{\numberline {A.3}Electron Gun Control Circuit}{43}{section.A.3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {A.3.1}Control Circuit}{43}{subsection.A.3.1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {A.5}{\ignorespaces Circuit Diagram for Electron Gun Control\relax }}{45}{figure.A.5}}
+\newlabel{electron_gun.pdf}{{A.5}{45}{Circuit Diagram for Electron Gun Control\relax \relax }{figure.A.5}{}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {A.3.2}The Ammeters}{46}{subsection.A.3.2}}
\@setckpt{appendices/electron_gun_circuit}{
-\setcounter{page}{43}
+\setcounter{page}{47}
\setcounter{equation}{0}
\setcounter{enumi}{4}
\setcounter{enumii}{0}
\setcounter{footnote}{1}
\setcounter{mpfootnote}{0}
\setcounter{part}{0}
-\setcounter{chapter}{0}
-\setcounter{section}{1}
-\setcounter{subsection}{1}
+\setcounter{chapter}{1}
+\setcounter{section}{3}
+\setcounter{subsection}{2}
\setcounter{subsubsection}{0}
\setcounter{paragraph}{0}
\setcounter{subparagraph}{0}
\setcounter{ContinuedFloat}{0}
\setcounter{r@tfl@t}{0}
\setcounter{parentequation}{0}
-\setcounter{Item}{17}
-\setcounter{Hfootnote}{5}
+\setcounter{Item}{30}
+\setcounter{Hfootnote}{6}
\setcounter{float@type}{4}
\setcounter{theorem}{0}
\setcounter{example}{0}
-\chapter*{Appendix - Electron Gun Control Circuit}
+\section{Electron Gun Control Circuit}
+
+\subsection{Control Circuit}
The control circuit diagram for the electron gun is shown in Figure \ref{electron_gun.pdf}. The wiring of the circuit, including resistors and potentiometers, was incoroprated into a single box, with external connections available for the power supplies, ammeters, electron gun, and sample holder. Both the components and operation of this circuit are straightforward; we will give a brief overview here for completeness.
\end{itemize}
\begin{landscape}
\begin{center}
- \includegraphics[scale=0.80]{figures/egun/electron_gun.pdf}
+ \includegraphics[scale=0.75]{figures/egun/electron_gun.pdf}
\captionof{figure}{Circuit Diagram for Electron Gun Control}
\label{electron_gun.pdf}
\end{center}
+\end{landscape}
+
\subsection{The Ammeters}
An ideal ammeter has no input resistance. In reality, it is not the current that is measured, but the voltage accross a fixed input resistor. This voltage can either be amplified, or the resistance increased, for measuring a smaller current.
+Since there is a voltage drop across the ammeter, the potential of the surface relative to the cathode is actually $U + I R$, where $R$ is the input resistance of the ammeter.
+
The 602 and 610B electrometers both provide a large range of scales and amplifier settings for current measurement. Using a low scale setting increases the input impedance, which increases the potential drop accross the ammeter. However, using a large amplifier gain increases noise; hence there is a trade off. For the 602 and 610B electrometers, a significant drift (typical +5\% of scale in 10min) in the zero level was also observed at high amplifier gains, whilst low gains appeared more stable (+10\% noted after 2 days).
-\end{landscape}
+
-\chapter*{Appendix - Electron Gun Control Circuit}
+\section{Electron Gun Control Circuit}
+
+\subsection{Control Circuit}
The control circuit diagram for the electron gun is shown in Figure \ref{electron_gun.pdf}. The wiring of the circuit, including resistors and potentiometers, was incoroprated into a single box, with external connections available for the power supplies, ammeters, electron gun, and sample holder. Both the components and operation of this circuit are straightforward; we will give a brief overview here for completeness.
\end{itemize}
\begin{landscape}
\begin{center}
- \includegraphics[scale=0.80]{figures/egun/electron_gun.pdf}
+ \includegraphics[scale=0.75]{figures/egun/electron_gun.pdf}
\captionof{figure}{Circuit Diagram for Electron Gun Control}
\label{electron_gun.pdf}
\end{center}
+
\end{landscape}
+
+\section{The Ammeters}
+
+An ideal ammeter has no input resistance. In reality, it is not the current that is measured, but the voltage accross a fixed input resistor. This voltage can either be amplified, or the resistance increased, for measuring a smaller current.
+
+Since there is a voltage drop across the ammeter, the potential of the surface relative to the cathode is actually $U + I R$, where $R$ is the input resistance of the ammeter.
+
+The 602 and 610B electrometers both provide a large range of scales and amplifier settings for current measurement. Using a low scale setting increases the input impedance, which increases the potential drop accross the ammeter. However, using a large amplifier gain increases noise; hence there is a trade off. For the 602 and 610B electrometers, a significant drift (typical +5\% of scale in 10min) in the zero level was also observed at high amplifier gains, whilst low gains appeared more stable (+10\% noted after 2 days).
+
\relax
-\@writefile{toc}{\contentsline {section}{\numberline {.1}A two dimensional electron gun simulation}{38}{section..1}}
-\@writefile{lof}{\contentsline {figure}{\numberline {3}{\ignorespaces {\bf 2D Simulation of trajectories of electrons accelerated through an electron gun}\relax }}{38}{figure..3}}
-\newlabel{egun_simulation1.pdf}{{3}{38}{{\bf 2D Simulation of trajectories of electrons accelerated through an electron gun}\relax \relax }{figure..3}{}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4}{\ignorespaces {\bf 2D Simulation of the electrostatic potential produced by the electron gun}\relax }}{38}{figure..4}}
-\newlabel{egun_simulation2.pdf}{{4}{38}{{\bf 2D Simulation of the electrostatic potential produced by the electron gun}\relax \relax }{figure..4}{}}
+\@writefile{toc}{\contentsline {section}{\numberline {A.2}Electron Optics}{40}{section.A.2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {A.2.1}A two dimensional electron gun simulation}{42}{subsection.A.2.1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {A.3}{\ignorespaces {\bf 2D Simulation of trajectories of electrons accelerated through an electron gun}\relax }}{42}{figure.A.3}}
+\newlabel{egun_simulation1.pdf}{{A.3}{42}{{\bf 2D Simulation of trajectories of electrons accelerated through an electron gun}\relax \relax }{figure.A.3}{}}
+\@writefile{lof}{\contentsline {figure}{\numberline {A.4}{\ignorespaces {\bf 2D Simulation of the electrostatic potential produced by the electron gun}\relax }}{42}{figure.A.4}}
+\newlabel{egun_simulation2.pdf}{{A.4}{42}{{\bf 2D Simulation of the electrostatic potential produced by the electron gun}\relax \relax }{figure.A.4}{}}
\@setckpt{appendices/electron_optics}{
-\setcounter{page}{39}
+\setcounter{page}{43}
\setcounter{equation}{0}
\setcounter{enumi}{4}
\setcounter{enumii}{0}
\setcounter{footnote}{1}
\setcounter{mpfootnote}{0}
\setcounter{part}{0}
-\setcounter{chapter}{0}
-\setcounter{section}{1}
-\setcounter{subsection}{0}
+\setcounter{chapter}{1}
+\setcounter{section}{2}
+\setcounter{subsection}{1}
\setcounter{subsubsection}{0}
\setcounter{paragraph}{0}
\setcounter{subparagraph}{0}
\setcounter{ContinuedFloat}{0}
\setcounter{r@tfl@t}{0}
\setcounter{parentequation}{0}
-\setcounter{Item}{17}
-\setcounter{Hfootnote}{5}
+\setcounter{Item}{30}
+\setcounter{Hfootnote}{6}
\setcounter{float@type}{4}
\setcounter{theorem}{0}
\setcounter{example}{0}
-\setcounter{section@level}{1}
+\setcounter{section@level}{2}
}
-\chapter*{Appendix - Electron Optics}
-
-
-There are two goals of electron optics as applied to total current spectroscopy (and other forms of electron scattering experiments): firstly, to produce the narrowest possible distribution $f(E - E_1)$ of primary electron energies at the sample, and secondly, to ensure that
+\section{Electron Optics}
The electron gun used for this study contains a total of ten electrodes, with six independently adjustable groups. Figure \ref{egun_simulation1.pdf} illustrates a cross section of the gun, using colour coding to indicate groups of electrodes which are kept at the same potential.
The first electrode, which houses the cathode, providing a narrow apparture for electrons to exit. A positive potential (of the order of $10V$ applied to the Wenhalt causes electrons leaving the cathode to be accelerated into a narrow beam.
- It is difficult to control the focusing properties of the gun using the Wenhalt alone; the main purpose of the Wenhalt is to create a high current, narrow beam of electrons, which can be focused by the other electrodes in the gun. If the potential applied to the Wenhalt is too high, electrons will be drawn into its surface. If the Wenhalt potential is too low, then the
+ It is difficult to control the focusing properties of the gun using the Wenhalt alone; the main purpose of the Wenhalt is to create a high current, narrow beam of electrons, which can be focused by the other electrodes in the gun. If the potential applied to the Wenhalt is too high, electrons will be drawn into its surface. If the Wenhalt potential is too low, then fewer electrons are able to leave the aparture.
\item {\bf Einzel Lens }
\item {\bf Final Electrode}
- The electron gun was originally designed for use in a Cathode Ray Oscilloscope (CRO). This electrode is held just in front of a flurescent screen, but is not electrically connected to the screen. When accellerated electrons strike the screen, they are
+ The electron gun was originally designed for use in a Cathode Ray Oscilloscope (CRO). This electrode is held just in front of a flurescent screen, but is not electrically connected to the screen. The final electrode is held at the same potential as the accelerating electrodes in the Einzel lens.
In the total current spectroscopy experiments, this electrode is typically at a much higher potential than the surface under bombardment. As a result, low energy primary electrons may be deflected or even turned back towards the gun, rather than striking the surface. This effect can be exploited to narrow the energy distribution of primary electrons at the surface, but also has the effect of greatly reducing the current of primary electrons reaching the surface.
\end{enumerate}
In preparation for Total Current Spectroscopy experiments, the effect of each of the controllable potentials was investigated by focusing the electron gun on its original flurescent screen. However, when repurposed for total current spectroscopy, the gun needed to be refocused several times (with changing sample holder design).
-From \ref{tcs_theory1}, it is apparent that the electron gun should be focused to achieve the maximum possible resolution by producing the narrowest possible primary energy distribution at the target. In addition, to increase the energy range (relative to the target), it
-
The gun was focused using an iterative process, by which each potential was altered in turn to maximise the current.
\pagebreak
-\section{A two dimensional electron gun simulation}
+\subsection{A two dimensional electron gun simulation}
The below figures \ref{egun_simulation1.pdf} and \ref{egun_simulation2.pdf} are the results of a simplistic electron gun simulation. The results of this simulation were not used to focus the actual electron gun; the images shown here are purely presented as a visual aid.
-\appendix{Electron Optics}
-
-
-There are two goals of electron optics as applied to total current spectroscopy (and other forms of electron scattering experiments): firstly, to produce the narrowest possible distribution $f(E - E_1)$ of primary electron energies at the sample, and secondly, to ensure that
+\section{Electron Optics}
The electron gun used for this study contains a total of ten electrodes, with six independently adjustable groups. Figure \ref{egun_simulation1.pdf} illustrates a cross section of the gun, using colour coding to indicate groups of electrodes which are kept at the same potential.
The first electrode, which houses the cathode, providing a narrow apparture for electrons to exit. A positive potential (of the order of $10V$ applied to the Wenhalt causes electrons leaving the cathode to be accelerated into a narrow beam.
- It is difficult to control the focusing properties of the gun using the Wenhalt alone; the main purpose of the Wenhalt is to create a high current, narrow beam of electrons, which can be focused by the other electrodes in the gun. If the potential applied to the Wenhalt is too high, electrons will be drawn into its surface. If the Wenhalt potential is too low, then the
+ It is difficult to control the focusing properties of the gun using the Wenhalt alone; the main purpose of the Wenhalt is to create a high current, narrow beam of electrons, which can be focused by the other electrodes in the gun. If the potential applied to the Wenhalt is too high, electrons will be drawn into its surface. If the Wenhalt potential is too low, then fewer electrons are able to leave the aparture.
\item {\bf Einzel Lens }
\item {\bf Final Electrode}
- The electron gun was originally designed for use in a Cathode Ray Oscilloscope (CRO). This electrode is held just in front of a flurescent screen, but is not electrically connected to the screen. When accellerated electrons strike the screen, they are
+ The electron gun was originally designed for use in a Cathode Ray Oscilloscope (CRO). This electrode is held just in front of a flurescent screen, but is not electrically connected to the screen. The final electrode is held at the same potential as the accelerating electrodes in the Einzel lens.
In the total current spectroscopy experiments, this electrode is typically at a much higher potential than the surface under bombardment. As a result, low energy primary electrons may be deflected or even turned back towards the gun, rather than striking the surface. This effect can be exploited to narrow the energy distribution of primary electrons at the surface, but also has the effect of greatly reducing the current of primary electrons reaching the surface.
\end{enumerate}
In preparation for Total Current Spectroscopy experiments, the effect of each of the controllable potentials was investigated by focusing the electron gun on its original flurescent screen. However, when repurposed for total current spectroscopy, the gun needed to be refocused several times (with changing sample holder design).
-From \ref{tcs_theory1}, it is apparent that the electron gun should be focused to achieve the maximum possible resolution by producing the narrowest possible primary energy distribution at the target. In addition, to increase the energy range (relative to the target), it
-
The gun was focused using an iterative process, by which each potential was altered in turn to maximise the current.
\pagebreak
-\section{A two dimensional electron gun simulation}
+\subsection{A two dimensional electron gun simulation}
The below figures \ref{egun_simulation1.pdf} and \ref{egun_simulation2.pdf} are the results of a simplistic electron gun simulation. The results of this simulation were not used to focus the actual electron gun; the images shown here are purely presented as a visual aid.
\relax
-\@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces An unprocessed and smoothed I(E) curve for a Si sample.\relax }}{35}{figure.caption.37}}
-\newlabel{siI.eps}{{1}{35}{An unprocessed and smoothed I(E) curve for a Si sample.\relax \relax }{figure.caption.37}{}}
-\@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces The effect of smoothing the original I(E) curve on its derivative.\relax }}{35}{figure.caption.38}}
-\newlabel{siI_tcs.eps}{{2}{35}{The effect of smoothing the original I(E) curve on its derivative.\relax \relax }{figure.caption.38}{}}
+\@writefile{toc}{\contentsline {section}{\numberline {A.1}Effect of Noise on the TCS Curve}{38}{section.A.1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {A.1}{\ignorespaces An unprocessed and smoothed I(E) curve for a Si sample.\relax }}{39}{figure.caption.39}}
+\newlabel{siI.eps}{{A.1}{39}{An unprocessed and smoothed I(E) curve for a Si sample.\relax \relax }{figure.caption.39}{}}
+\@writefile{lof}{\contentsline {figure}{\numberline {A.2}{\ignorespaces The effect of smoothing the original I(E) curve on its derivative.\relax }}{39}{figure.caption.40}}
+\newlabel{siI_tcs.eps}{{A.2}{39}{The effect of smoothing the original I(E) curve on its derivative.\relax \relax }{figure.caption.40}{}}
\@setckpt{appendices/tcs_noise}{
-\setcounter{page}{36}
+\setcounter{page}{40}
\setcounter{equation}{0}
\setcounter{enumi}{5}
\setcounter{enumii}{0}
\setcounter{footnote}{1}
\setcounter{mpfootnote}{0}
\setcounter{part}{0}
-\setcounter{chapter}{0}
-\setcounter{section}{0}
-\setcounter{subsection}{7}
+\setcounter{chapter}{1}
+\setcounter{section}{1}
+\setcounter{subsection}{0}
\setcounter{subsubsection}{0}
\setcounter{paragraph}{0}
\setcounter{subparagraph}{0}
\setcounter{ContinuedFloat}{0}
\setcounter{r@tfl@t}{0}
\setcounter{parentequation}{0}
-\setcounter{Item}{13}
-\setcounter{Hfootnote}{5}
+\setcounter{Item}{26}
+\setcounter{Hfootnote}{6}
\setcounter{float@type}{4}
\setcounter{theorem}{0}
\setcounter{example}{0}
-\setcounter{section@level}{2}
+\setcounter{section@level}{1}
}
-\chapter*{Appendix - Effect of Noise on the TCS Curve}
+\section{Effect of Noise on the TCS Curve}
-Taking the derivative of discrete data is problematic. Using a centred difference finite derivative approximation:
+Taking the derivative of discrete data is problematic. Consider a function $f(x)$. Using a centred difference finite derivative approximation:
\begin{align*}
\der{f}{x} &= \frac{f(x + h) - f(x - h)}{h} + O(h^2)
\end{align*}
The accuraracy of this approximation increases as $h \to 0$\footnote{Ignoring any effects due to rounding of floating point numbers}.
-However, if $f_s(x)$ is the result of sampling $f(x)$, with $\Delta f$ the uncertainty in a measurement:
+If $f_s(x)$ is the result of sampling $f(x)$, with $\Delta f$ the uncertainty in a measurement, then we can calculate the final uncertainty when finite differences are used to approximate $\der{f}{x}$:
\begin{align*}
f_s(x) &= f(x) \pm \Delta f \\
\der{f_s}{x} &\approx \der{f}{x} \\
\end{align*}
The uncertainty in the sampled derivative has a pole at $h = 0$.
+
{\emph Note: I now suspect that this is a major reason why Komolov has used Lock-in amplifiers}
-The problem may be fixed [dodged?] by increasing $h$ (in which case the resolution of the derivative is decreased dramatically), or application of smoothing averages (which also decrease the resolution, but not as much). \emph{Needs rephrasing}
-Smoothing of the sampled curve $f_s(x)$ (by application of a moving average) will reduce the deviation of points the smooth curve which best fits the data. As shown in Figures \ref{siI.eps} and \ref{siI_tcs.eps}, smoothing of $f_s(x)$ has a far greater effect on the derivative of $f_s$ than on $f_s$ itself.
+Smoothing of the sampled points $f_s(x)$ (by application of a moving average) will reduce the deviation of points the smooth curve which best fits the data; We can think of the points $f_s(x)$ as sampling a \emph{different} function to $f(x)$, but with smaller uncertainties. Smoothing of the original sampled points removes fine structure.
+
+The alternative is to increase $h$.
+
+As shown in Figures \ref{siI.eps} and \ref{siI_tcs.eps}, smoothing of $f_s(x)$ has a far greater effect on the derivative of $f_s$ than on $f_s$ itself.
+
+\emph{TODO: Calculate MSE for both curves}
+\emph{TODO: Show curves created with large $h$}
\begin{figure}[H]
-\chapter*{Appendix - Effect of Noise on the TCS Curve}
+\section{Effect of Noise on the TCS Curve}
-Taking the derivative of discrete data is problematic. Using a centred difference finite derivative approximation:
+Taking the derivative of discrete data is problematic. Consider a function $f(x)$. Using a centred difference finite derivative approximation:
\begin{align*}
\der{f}{x} &= \frac{f(x + h) - f(x - h)}{h} + O(h^2)
\end{align*}
The accuraracy of this approximation increases as $h \to 0$\footnote{Ignoring any effects due to rounding of floating point numbers}.
-However, if $f_s(x)$ is the result of sampling $f(x)$, with $\Delta f$ the uncertainty in a measurement:
+If $f_s(x)$ is the result of sampling $f(x)$, with $\Delta f$ the uncertainty in a measurement, then we can calculate the final uncertainty when finite differences are used to approximate $\der{f}{x}$:
\begin{align*}
f_s(x) &= f(x) \pm \Delta f \\
\der{f_s}{x} &\approx \der{f}{x} \\
\end{align*}
The uncertainty in the sampled derivative has a pole at $h = 0$.
+
{\emph Note: I now suspect that this is a major reason why Komolov has used Lock-in amplifiers}
-The problem may be fixed [dodged?] by increasing $h$ (in which case the resolution of the derivative is decreased dramatically), or application of smoothing averages (which also decrease the resolution, but not as much). \emph{Needs rephrasing}
-Smoothing of the sampled curve $f_s(x)$ (by application of a moving average) will reduce the deviation of points the smooth curve which best fits the data. As shown in Figures \ref{siI.eps} and \ref{siI_tcs.eps}, smoothing of $f_s(x)$ has a far greater effect on the derivative of $f_s$ than on $f_s$ itself.
+Smoothing of the sampled points $f_s(x)$ (by application of a moving average) will reduce the deviation of points the smooth curve which best fits the data; We can think of the points $f_s(x)$ as sampling a \emph{different} function to $f(x)$, but with smaller uncertainties. Smoothing of the original sampled points removes fine structure.
+
+The alternative is to increase $h$.
+
+As shown in Figures \ref{siI.eps} and \ref{siI_tcs.eps}, smoothing of $f_s(x)$ has a far greater effect on the derivative of $f_s$ than on $f_s$ itself.
+
+\emph{TODO: Calculate MSE for both curves}
+\emph{TODO: Show curves created with large $h$}
\begin{figure}[H]
\relax
-\@writefile{toc}{\contentsline {chapter}{\numberline {5}Conclusion}{32}{chapter.5}}
+\@writefile{toc}{\contentsline {chapter}{\numberline {5}Conclusion}{35}{chapter.5}}
\@writefile{lof}{\addvspace {10\p@ }}
\@writefile{lot}{\addvspace {10\p@ }}
\@setckpt{chapters/Conclusion}{
-\setcounter{page}{33}
+\setcounter{page}{36}
\setcounter{equation}{0}
\setcounter{enumi}{5}
\setcounter{enumii}{0}
\setcounter{enumiii}{0}
\setcounter{enumiv}{0}
-\setcounter{footnote}{0}
+\setcounter{footnote}{1}
\setcounter{mpfootnote}{0}
\setcounter{part}{0}
\setcounter{chapter}{5}
\setcounter{ContinuedFloat}{0}
\setcounter{r@tfl@t}{0}
\setcounter{parentequation}{0}
-\setcounter{Item}{13}
-\setcounter{Hfootnote}{4}
+\setcounter{Item}{26}
+\setcounter{Hfootnote}{5}
\setcounter{float@type}{4}
\setcounter{theorem}{0}
\setcounter{example}{0}
\chapter{Conclusion}
-We have demonstrated the use of multiple techniques for characterisation and analysis of metallic thin films. In particular we have focused on measurable differences in the properties of metallic-black thin films in comparison with bright metallic thin films.
+We have demonstrated the use of multiple techniques for characterisation and analysis of metallic thin films\footnote{(We have?)}. In particular we have found measurable differences in the properties of metallic-black thin films in comparison with bright metallic thin films. We just don't know what to say about them yet.
+
+
\chapter{Conclusion}
-We have demonstrated the use of multiple techniques for characterisation and analysis of metallic thin films. In particular we have focused on measurable differences in the properties of metallic-black thin films in comparison with bright metallic thin films.
+We have demonstrated the use of multiple techniques for characterisation and analysis of metallic thin films\footnote{(We have?)}. In particular we have found measurable differences in the properties of metallic-black thin films in comparison with bright metallic thin films. We just don't know what to say about them yet.
+
+
Motivation:
\begin{itemize}
\item The properties of solids can be understood in terms of an infinite periodic lattice
- \item In reality, every solid must have a finite spatial extent. The
- \item Thin films can have extremely complicated and interesting properties.
+ \item In reality, every solid must have a finite spatial extent. The surface is extremely important because it is the interface for all physical/chemical interactions with the solid and its environment.
+ \item Thin films can have extremely complicated and interesting properties.
\item The characterisation of thin films is important research in electronics as the surface to volume ratio increases.
- \item Most recent research has been into completely new technologies which exploit phenomena (
+ \item Most recent research has been into constructing ``meta-materials'' which can be exploited for nanoscale applications. Eg: plasmonic based circuitry.
\item Somehow link to metallic-black films (?)
\end{itemize}
+
+\emph{More about metallic-black films}
+
So called metallic-black films are the result of deposition of metal elements at a relatively high pressure (of the order of $10^{-2}$ mbar). The films are named due to their high absorbance at visible wavelengths; they appear black to the naked eye. There is a remarkable contrast between such films and films deposited under low pressure (less than $10^{-6}$mbar), which are typically highly reflective and brightly coloured.
% First mentions and early research; Pfund
% What I will be doing with metallic-black films
This project will employ several techniques, including:Total Current Specroscopy; Ellipsometry and Optical Spectroscopy to investigate the difference between metallic films deposited at low pressure, and high pressure (metallic-blacks).
+This report will be organised as follows...
+You just read the introduction, which comes first. After that we talk about theory and then experimental stuff.
+
Motivation:
\begin{itemize}
\item The properties of solids can be understood in terms of an infinite periodic lattice
- \item In reality, every solid must have a finite spatial extent. The
- \item Thin films can have extremely complicated and interesting properties.
+ \item In reality, every solid must have a finite spatial extent. The surface is extremely important because it is the interface for all physical/chemical interactions with the solid and its environment.
+ \item Thin films can have extremely complicated and interesting properties.
\item The characterisation of thin films is important research in electronics as the surface to volume ratio increases.
- \item Most recent research has been into completely new technologies which exploit the p
+ \item Most recent research has been into constructing ``meta-materials'' which can be exploited for nanoscale applications. Eg: plasmonic based circuitry.
\item Somehow link to metallic-black films (?)
\end{itemize}
+
+\emph{More about metallic-black films}
+
So called metallic-black films are the result of deposition of metal elements at a relatively high pressure (of the order of $10^{-2}$ mbar). The films are named due to their high absorbance at visible wavelengths; they appear black to the naked eye. There is a remarkable contrast between such films and films deposited under low pressure (less than $10^{-6}$mbar), which are typically highly reflective and brightly coloured.
% First mentions and early research; Pfund
\relax
-\@writefile{toc}{\contentsline {chapter}{\numberline {4}Results and Discussion}{10}{chapter.4}}
+\@writefile{toc}{\contentsline {chapter}{\numberline {4}Results and Discussion}{12}{chapter.4}}
\@writefile{lof}{\addvspace {10\p@ }}
\@writefile{lot}{\addvspace {10\p@ }}
-\@writefile{toc}{\contentsline {section}{\numberline {4.1}Scanning Electron Microscopy}{10}{section.4.1}}
-\newlabel{SEM_images}{{4.1}{10}{Scanning Electron Microscopy\relax }{section.4.1}{}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.1}{\ignorespaces {\bf 2500 x 1900nm SEM images of Au-Black (left) and Au-Bright (right) deposited on Si} Preparation pressures were $2\times 10^{-2}$mbar and $1\times 10^{-6}$mbar respectively. The films are sufficiently thick to be able to observe the colour with the naked eye.\relax }}{10}{figure.4.1}}
-\newlabel{dft}{{4.1}{11}{Fourier Analysis of SEM Images\relax }{equation.4.1.1}{}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.2}{\ignorespaces Amplitude density plot of DFT for Au-Black SEM image\relax }}{12}{figure.4.2}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.3}{\ignorespaces Amplitude density plot of DFT for Au-Bright SEM image\relax }}{12}{figure.4.3}}
-\@writefile{toc}{\contentsline {subsection}{\numberline {4.1.1}Higher Magnification Images of Au-Black}{13}{subsection.4.1.1}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.4}{\ignorespaces Increasing magnification images of Au-Black\relax }}{13}{figure.caption.10}}
-\newlabel{Au_BLACK_increasing_magnifications.jpg}{{4.4}{13}{Increasing magnification images of Au-Black\relax \relax }{figure.caption.10}{}}
-\@writefile{toc}{\contentsline {section}{\numberline {4.2}Atomic Force Microscopy of Au}{13}{section.4.2}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.5}{\ignorespaces AFM amplitude image of Au-Bright\relax }}{13}{figure.caption.11}}
-\newlabel{afm/Au_BRIGHT_AFM.tif}{{4.5}{13}{AFM amplitude image of Au-Bright\relax \relax }{figure.caption.11}{}}
-\@writefile{toc}{\contentsline {section}{\numberline {4.3}Total Current Spectropy}{14}{section.4.3}}
-\@writefile{toc}{\contentsline {subsection}{\numberline {4.3.1}Effect of Focusing of the Electron Gun on the TCS}{14}{subsection.4.3.1}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.6}{\ignorespaces Comparison of TCS curves due to different sets of electron gun potentials; same sample (Au on Si).\relax }}{14}{figure.caption.12}}
-\newlabel{focus_accel_tcs.eps}{{4.6}{14}{Comparison of TCS curves due to different sets of electron gun potentials; same sample (Au on Si).\relax \relax }{figure.caption.12}{}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.7}{\ignorespaces Comparison of TCS curves due to different sets of electron gun potentials; same sample (Au on Si).\relax }}{15}{figure.caption.13}}
-\newlabel{focus_central_tcs.eps}{{4.7}{15}{Comparison of TCS curves due to different sets of electron gun potentials; same sample (Au on Si).\relax \relax }{figure.caption.13}{}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.8}{\ignorespaces Comparison of TCS curves due to different sets of electron gun potentials; same sample (Au on Si).\relax }}{15}{figure.caption.14}}
-\newlabel{focus_deflection_tcs.eps}{{4.8}{15}{Comparison of TCS curves due to different sets of electron gun potentials; same sample (Au on Si).\relax \relax }{figure.caption.14}{}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.9}{\ignorespaces Comparison of TCS curves due to different sets of electron gun potentials; same sample (Au on Si).\relax }}{16}{figure.caption.15}}
-\newlabel{focus_wenhault_tcs.eps}{{4.9}{16}{Comparison of TCS curves due to different sets of electron gun potentials; same sample (Au on Si).\relax \relax }{figure.caption.15}{}}
-\@writefile{toc}{\contentsline {subsection}{\numberline {4.3.2}Effect of Evaporation of Ag onto an Si substrate}{16}{subsection.4.3.2}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.10}{\ignorespaces Successive TCS curves for a BlackAg evaporated on Ag on a Si substrate.\relax }}{17}{figure.caption.16}}
-\newlabel{agsiI_tcs.eps}{{4.10}{17}{Successive TCS curves for a BlackAg evaporated on Ag on a Si substrate.\relax \relax }{figure.caption.16}{}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.11}{\ignorespaces The above TCS comparison repeated for a second sample (NB: Ag evaporation time is half that of the first sample; layer is still visible by eye)\relax }}{18}{figure.caption.17}}
-\newlabel{agsiII_tcs.eps}{{4.11}{18}{The above TCS comparison repeated for a second sample \\(NB: Ag evaporation time is half that of the first sample; layer is still visible by eye)\relax \relax }{figure.caption.17}{}}
-\@writefile{toc}{\contentsline {subsection}{\numberline {4.3.3}Effect of Evaporation of Au on Si}{18}{subsection.4.3.3}}
-\newlabel{increased_au_thickness_tcs.eps}{{\caption@xref {increased_au_thickness_tcs.eps}{ on input line 183}}{18}{Effect of Evaporation of Au on Si\relax }{figure.caption.18}{}}
-\newlabel{blackau_on_au_on_si_tcs.eps}{{\caption@xref {blackau_on_au_on_si_tcs.eps}{ on input line 190}}{19}{Effect of Evaporation of Au on Si\relax }{figure.caption.19}{}}
-\@writefile{toc}{\contentsline {section}{\numberline {4.4}Variable Angle Spectroscopy Ellipsometry}{20}{section.4.4}}
-\@writefile{toc}{\contentsline {subsection}{\numberline {4.4.1}Ag-Bright on Si substrate}{20}{subsection.4.4.1}}
-\newlabel{psi_final_model.png}{{\caption@xref {psi_final_model.png}{ on input line 204}}{20}{Ag-Bright on Si substrate\relax }{figure.caption.20}{}}
-\newlabel{delta_final_model.png}{{\caption@xref {delta_final_model.png}{ on input line 210}}{20}{Ag-Bright on Si substrate\relax }{figure.caption.21}{}}
-\newlabel{ag_fit_vs_bulk_opticalconstants.png}{{\caption@xref {ag_fit_vs_bulk_opticalconstants.png}{ on input line 216}}{20}{Ag-Bright on Si substrate\relax }{figure.caption.22}{}}
-\@writefile{lot}{\contentsline {table}{\numberline {4.1}{\ignorespaces Model for thin Ag on Si\relax }}{21}{table.4.1}}
-\@writefile{toc}{\contentsline {subsection}{\numberline {4.4.2}Black Ag on Si}{21}{subsection.4.4.2}}
-\newlabel{psi_final_model.png}{{\caption@xref {psi_final_model.png}{ on input line 239}}{21}{Black Ag on Si\relax }{figure.caption.23}{}}
-\newlabel{delta_final_model.png}{{\caption@xref {delta_final_model.png}{ on input line 245}}{22}{Black Ag on Si\relax }{figure.caption.24}{}}
-\newlabel{ag_fit_vs_bulk_opticalconstants.png}{{\caption@xref {ag_fit_vs_bulk_opticalconstants.png}{ on input line 251}}{22}{Black Ag on Si\relax }{figure.caption.25}{}}
-\@writefile{lot}{\contentsline {table}{\numberline {4.2}{\ignorespaces Model for thin Ag on Si\relax }}{22}{table.4.2}}
-\@writefile{toc}{\contentsline {section}{\numberline {4.5}Optical Transmission and Reflection Measurements using the VASE}{23}{section.4.5}}
-\@writefile{toc}{\contentsline {section}{\numberline {4.6}Optical Transmission Spectroscopy using OceanOptics Spectrometer}{24}{section.4.6}}
-\@writefile{toc}{\contentsline {subsection}{\numberline {4.6.1}Dark Spectrum}{24}{subsection.4.6.1}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.12}{\ignorespaces Dark spectra\relax }}{24}{figure.caption.26}}
-\newlabel{dark_comparison.eps}{{4.12}{24}{Dark spectra\relax \relax }{figure.caption.26}{}}
-\@writefile{toc}{\contentsline {subsection}{\numberline {4.6.2}Reference Spectrum}{25}{subsection.4.6.2}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.13}{\ignorespaces Xe Lamp reference spectra\relax }}{25}{figure.caption.27}}
-\newlabel{reference.eps}{{4.13}{25}{Xe Lamp reference spectra\relax \relax }{figure.caption.27}{}}
-\@writefile{toc}{\contentsline {subsection}{\numberline {4.6.3}Testing the Spectrometer}{26}{subsection.4.6.3}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.14}{\ignorespaces Tested Spectrometer with 653nm Filter\relax }}{26}{figure.caption.28}}
-\newlabel{653nm_filter.eps}{{4.14}{26}{Tested Spectrometer with 653nm Filter\relax \relax }{figure.caption.28}{}}
-\newlabel{transmission1}{{4.2}{26}{Testing the Spectrometer\relax }{equation.4.6.2}{}}
-\@writefile{toc}{\contentsline {subsection}{\numberline {4.6.4}Transmission Spectra of Glass}{26}{subsection.4.6.4}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.15}{\ignorespaces Glass reference transmission spectrum\relax }}{27}{figure.caption.29}}
-\newlabel{glass_transmission.eps}{{4.15}{27}{Glass reference transmission spectrum\relax \relax }{figure.caption.29}{}}
-\@writefile{toc}{\contentsline {subsection}{\numberline {4.6.5}Transmission Spectra of Au and Au-Black on Glass}{27}{subsection.4.6.5}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.16}{\ignorespaces Transmission Spectra for various Au films\relax }}{28}{figure.caption.30}}
-\newlabel{blackau_vs_au.eps}{{4.16}{28}{Transmission Spectra for various Au films\relax \relax }{figure.caption.30}{}}
-\@writefile{toc}{\contentsline {subsubsection}{Effect of Atmosphere on Transmission Spectra of Au-Black}{29}{section*.31}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.17}{\ignorespaces Transmission Spectra for Black Au films prepared in different atmospheres\relax }}{29}{figure.caption.32}}
-\newlabel{he_blackau_vs_air_blackau.eps}{{4.17}{29}{Transmission Spectra for Black Au films prepared in different atmospheres\relax \relax }{figure.caption.32}{}}
-\@writefile{toc}{\contentsline {subsection}{\numberline {4.6.6}Transmission Spectra of Ag}{29}{subsection.4.6.6}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.18}{\ignorespaces Transmission Spectra for a Silver film on glass\relax }}{30}{figure.caption.33}}
-\newlabel{silver_transmission.eps}{{4.18}{30}{Transmission Spectra for a Silver film on glass\relax \relax }{figure.caption.33}{}}
-\@writefile{toc}{\contentsline {subsection}{\numberline {4.6.7}Transmission Spectra of Ag and Ag-Black on Glass}{30}{subsection.4.6.7}}
-\@writefile{lof}{\contentsline {figure}{\numberline {4.19}{\ignorespaces Transmission Spectra for a Silver film on glass\relax }}{31}{figure.caption.34}}
-\newlabel{blackag_vs_ag.eps}{{4.19}{31}{Transmission Spectra for a Silver film on glass\relax \relax }{figure.caption.34}{}}
+\@writefile{toc}{\contentsline {section}{\numberline {4.1}Scanning Electron Microscopy}{12}{section.4.1}}
+\newlabel{SEM_images}{{4.1}{12}{Scanning Electron Microscopy\relax }{section.4.1}{}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.1}{\ignorespaces {\bf 2500 x 1900nm SEM images of Au-Black (left) and Au-Bright (right) deposited on Si} Preparation pressures were $2\times 10^{-2}$mbar and $1\times 10^{-6}$mbar respectively. The films are sufficiently thick to be able to observe the colour with the naked eye.\relax }}{12}{figure.4.1}}
+\newlabel{dft}{{4.1}{13}{Fourier Analysis of SEM Images\relax }{equation.4.1.1}{}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.2}{\ignorespaces Amplitude density plot of DFT for Au-Black SEM image\relax }}{14}{figure.4.2}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.3}{\ignorespaces Amplitude density plot of DFT for Au-Bright SEM image\relax }}{14}{figure.4.3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {4.1.1}Higher Magnification Images of Au-Black}{15}{subsection.4.1.1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.4}{\ignorespaces Increasing magnification images of Au-Black\relax }}{15}{figure.caption.10}}
+\newlabel{Au_BLACK_increasing_magnifications.jpg}{{4.4}{15}{Increasing magnification images of Au-Black\relax \relax }{figure.caption.10}{}}
+\@writefile{toc}{\contentsline {section}{\numberline {4.2}Atomic Force Microscopy of Au}{15}{section.4.2}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.5}{\ignorespaces AFM amplitude image of Au-Bright\relax }}{15}{figure.caption.11}}
+\newlabel{afm/Au_BRIGHT_AFM.tif}{{4.5}{15}{AFM amplitude image of Au-Bright\relax \relax }{figure.caption.11}{}}
+\@writefile{toc}{\contentsline {section}{\numberline {4.3}Total Current Spectropy}{16}{section.4.3}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {4.3.1}Effect of Focusing of the Electron Gun on the TCS}{16}{subsection.4.3.1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.6}{\ignorespaces Comparison of TCS curves due to different sets of electron gun potentials; same sample (Au on Si).\relax }}{16}{figure.caption.12}}
+\newlabel{focus_accel_tcs.eps}{{4.6}{16}{Comparison of TCS curves due to different sets of electron gun potentials; same sample (Au on Si).\relax \relax }{figure.caption.12}{}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.7}{\ignorespaces Comparison of TCS curves due to different sets of electron gun potentials; same sample (Au on Si).\relax }}{17}{figure.caption.13}}
+\newlabel{focus_central_tcs.eps}{{4.7}{17}{Comparison of TCS curves due to different sets of electron gun potentials; same sample (Au on Si).\relax \relax }{figure.caption.13}{}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.8}{\ignorespaces Comparison of TCS curves due to different sets of electron gun potentials; same sample (Au on Si).\relax }}{17}{figure.caption.14}}
+\newlabel{focus_deflection_tcs.eps}{{4.8}{17}{Comparison of TCS curves due to different sets of electron gun potentials; same sample (Au on Si).\relax \relax }{figure.caption.14}{}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.9}{\ignorespaces Comparison of TCS curves due to different sets of electron gun potentials; same sample (Au on Si).\relax }}{18}{figure.caption.15}}
+\newlabel{focus_wenhault_tcs.eps}{{4.9}{18}{Comparison of TCS curves due to different sets of electron gun potentials; same sample (Au on Si).\relax \relax }{figure.caption.15}{}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {4.3.2}Effect of Evaporation of Ag onto an Si substrate}{18}{subsection.4.3.2}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.10}{\ignorespaces Successive TCS curves for a BlackAg evaporated on Ag on a Si substrate.\relax }}{19}{figure.caption.16}}
+\newlabel{agsiI_tcs.eps}{{4.10}{19}{Successive TCS curves for a BlackAg evaporated on Ag on a Si substrate.\relax \relax }{figure.caption.16}{}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.11}{\ignorespaces The above TCS comparison repeated for a second sample (NB: Ag evaporation time is half that of the first sample; layer is still visible by eye)\relax }}{20}{figure.caption.17}}
+\newlabel{agsiII_tcs.eps}{{4.11}{20}{The above TCS comparison repeated for a second sample \\(NB: Ag evaporation time is half that of the first sample; layer is still visible by eye)\relax \relax }{figure.caption.17}{}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {4.3.3}Effect of Evaporation of Au on Si}{20}{subsection.4.3.3}}
+\newlabel{increased_au_thickness_tcs.eps}{{\caption@xref {increased_au_thickness_tcs.eps}{ on input line 183}}{20}{Effect of Evaporation of Au on Si\relax }{figure.caption.18}{}}
+\newlabel{blackau_on_au_on_si_tcs.eps}{{\caption@xref {blackau_on_au_on_si_tcs.eps}{ on input line 190}}{21}{Effect of Evaporation of Au on Si\relax }{figure.caption.19}{}}
+\@writefile{toc}{\contentsline {section}{\numberline {4.4}Variable Angle Spectroscopy Ellipsometry}{22}{section.4.4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {4.4.1}Ag-Bright on Si substrate}{22}{subsection.4.4.1}}
+\newlabel{psi_final_model.png}{{\caption@xref {psi_final_model.png}{ on input line 204}}{22}{Ag-Bright on Si substrate\relax }{figure.caption.20}{}}
+\newlabel{delta_final_model.png}{{\caption@xref {delta_final_model.png}{ on input line 210}}{22}{Ag-Bright on Si substrate\relax }{figure.caption.21}{}}
+\newlabel{ag_fit_vs_bulk_opticalconstants.png}{{\caption@xref {ag_fit_vs_bulk_opticalconstants.png}{ on input line 216}}{22}{Ag-Bright on Si substrate\relax }{figure.caption.22}{}}
+\@writefile{lot}{\contentsline {table}{\numberline {4.1}{\ignorespaces Model for thin Ag on Si\relax }}{23}{table.4.1}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {4.4.2}Black Ag on Si}{23}{subsection.4.4.2}}
+\newlabel{psi_final_model.png}{{\caption@xref {psi_final_model.png}{ on input line 239}}{23}{Black Ag on Si\relax }{figure.caption.23}{}}
+\newlabel{delta_final_model.png}{{\caption@xref {delta_final_model.png}{ on input line 245}}{24}{Black Ag on Si\relax }{figure.caption.24}{}}
+\newlabel{ag_fit_vs_bulk_opticalconstants.png}{{\caption@xref {ag_fit_vs_bulk_opticalconstants.png}{ on input line 251}}{24}{Black Ag on Si\relax }{figure.caption.25}{}}
+\@writefile{lot}{\contentsline {table}{\numberline {4.2}{\ignorespaces Model for thin Ag on Si\relax }}{24}{table.4.2}}
+\@writefile{toc}{\contentsline {section}{\numberline {4.5}Optical Reflection Spectroscopy using the VASE}{25}{section.4.5}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {4.5.1}Au on Si}{25}{subsection.4.5.1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.12}{\ignorespaces figure\relax }}{25}{figure.caption.26}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {4.5.2}Au on Au-Black on Au on Si}{25}{subsection.4.5.2}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.13}{\ignorespaces figure\relax }}{25}{figure.caption.27}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {4.5.3}Comparison with model of 50nm Au on Si}{26}{subsection.4.5.3}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.14}{\ignorespaces Generated 50nm on Si\relax }}{26}{figure.caption.28}}
+\@writefile{toc}{\contentsline {section}{\numberline {4.6}Optical Transmission Spectroscopy using OceanOptics Spectrometer}{27}{section.4.6}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {4.6.1}Dark Spectrum}{27}{subsection.4.6.1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.15}{\ignorespaces Dark spectra\relax }}{27}{figure.caption.29}}
+\newlabel{dark_comparison.eps}{{4.15}{27}{Dark spectra\relax \relax }{figure.caption.29}{}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {4.6.2}Reference Spectrum}{28}{subsection.4.6.2}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.16}{\ignorespaces Xe Lamp reference spectra\relax }}{28}{figure.caption.30}}
+\newlabel{reference.eps}{{4.16}{28}{Xe Lamp reference spectra\relax \relax }{figure.caption.30}{}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {4.6.3}Testing the Spectrometer}{29}{subsection.4.6.3}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.17}{\ignorespaces Tested Spectrometer with 653nm Filter\relax }}{29}{figure.caption.31}}
+\newlabel{653nm_filter.eps}{{4.17}{29}{Tested Spectrometer with 653nm Filter\relax \relax }{figure.caption.31}{}}
+\newlabel{transmission1}{{4.2}{29}{Testing the Spectrometer\relax }{equation.4.6.2}{}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {4.6.4}Transmission Spectra of Glass}{29}{subsection.4.6.4}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.18}{\ignorespaces Glass reference transmission spectrum\relax }}{30}{figure.caption.32}}
+\newlabel{glass_transmission.eps}{{4.18}{30}{Glass reference transmission spectrum\relax \relax }{figure.caption.32}{}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {4.6.5}Transmission Spectra of Au and Au-Black on Glass}{30}{subsection.4.6.5}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.19}{\ignorespaces Transmission Spectra for various Au films\relax }}{31}{figure.caption.33}}
+\newlabel{blackau_vs_au.eps}{{4.19}{31}{Transmission Spectra for various Au films\relax \relax }{figure.caption.33}{}}
+\@writefile{toc}{\contentsline {subsubsection}{Effect of Atmosphere on Transmission Spectra of Au-Black}{32}{section*.34}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.20}{\ignorespaces Transmission Spectra for Black Au films prepared in different atmospheres\relax }}{32}{figure.caption.35}}
+\newlabel{he_blackau_vs_air_blackau.eps}{{4.20}{32}{Transmission Spectra for Black Au films prepared in different atmospheres\relax \relax }{figure.caption.35}{}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {4.6.6}Transmission Spectra of Ag}{32}{subsection.4.6.6}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.21}{\ignorespaces Transmission Spectra for a Silver film on glass\relax }}{33}{figure.caption.36}}
+\newlabel{silver_transmission.eps}{{4.21}{33}{Transmission Spectra for a Silver film on glass\relax \relax }{figure.caption.36}{}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {4.6.7}Transmission Spectra of Ag and Ag-Black on Glass}{33}{subsection.4.6.7}}
+\@writefile{lof}{\contentsline {figure}{\numberline {4.22}{\ignorespaces Transmission Spectra for a Silver film on glass\relax }}{34}{figure.caption.37}}
+\newlabel{blackag_vs_ag.eps}{{4.22}{34}{Transmission Spectra for a Silver film on glass\relax \relax }{figure.caption.37}{}}
\@setckpt{chapters/Results}{
-\setcounter{page}{32}
+\setcounter{page}{35}
\setcounter{equation}{2}
\setcounter{enumi}{5}
\setcounter{enumii}{0}
\setcounter{subsubsection}{0}
\setcounter{paragraph}{0}
\setcounter{subparagraph}{0}
-\setcounter{figure}{19}
+\setcounter{figure}{22}
\setcounter{table}{2}
\setcounter{ContinuedFloat}{0}
\setcounter{r@tfl@t}{0}
\setcounter{parentequation}{0}
-\setcounter{Item}{13}
+\setcounter{Item}{26}
\setcounter{Hfootnote}{4}
\setcounter{float@type}{4}
\setcounter{theorem}{0}
There are two notable differences between the SEM images. Firstly, the central peak in low frequency components appears isotropic for the Au-Black sample, but is elliptically shaped for the Au-Bright image, indicating a. Secondly the
-Equation \eqref{dft} actually gives the Fourier coefficients of the infinite periodic extension of $f(x, y)$. If $f(x, y)$ is not periodic, then applying \eqref{dft} introduces extra high frequency components due to sharp discontinuities at the boundaries. The central
+Equation \eqref{dft} actually gives the Fourier coefficients of the infinite periodic extension of $f(x, y)$. If $f(x, y)$ is not periodic, then applying \eqref{dft} introduces extra high frequency components due to sharp discontinuities at the boundaries. (I think this is why FFTs show the perpendicular lines running through the centre... you can apply windows to reduce this effect, but since this is qualitative I haven't bothered).
\pagebreak
\begin{center}
\pagebreak
-\section{Optical Transmission and Reflection Measurements using the VASE}
+\section{Optical Reflection Spectroscopy using the VASE}
+
+\subsection{Au on Si}
+
+\begin{figure}[H]
+ \centering
+ \includegraphics[width=0.8\textwidth]{figures/ellipsometer/au_and_blackau/au_on_si.png}
+ \caption{figure}{Reflection measurements for Au layers on Si}
+\end{figure}
+
+
+\subsection{Au on Au-Black on Au on Si}
+\begin{figure}[H]
+ \centering
+ \includegraphics[width=0.8\textwidth]{figures/ellipsometer/au_and_blackau/au_on_blackau_si.png}
+ \caption{figure}{Reflection measurements for an Au layer on Au-Black on Au layers on Si}
+\end{figure}
+
+\subsection{Comparison with model of 50nm Au on Si}
+
+\begin{figure}[H]
+ \centering
+ \includegraphics[width=0.8\textwidth]{figures/ellipsometer/au_and_blackau/generated_au_on_si_reflection.png}
+ \caption{Generated 50nm on Si}
+\end{figure}
\pagebreak
\begin{center}
-
\begin{tabular}{cc}
\includegraphics[scale=0.20]{figures/sem/Au_BLACK_200nm.png} & %\captionof{figure}{Au-Black SEM Image} \label{Au_BLACK_200nm.png} &
\includegraphics[scale=0.20]{figures/sem/Au_semi-shiny_1_SEM.png} %\captionof{figure}{Au SEM Image} \label{Au_semi-shiny_1_SEM.png}
There are two notable differences between the SEM images. Firstly, the central peak in low frequency components appears isotropic for the Au-Black sample, but is elliptically shaped for the Au-Bright image, indicating a. Secondly the
-Equation \eqref{dft} actually gives the Fourier coefficients of the infinite periodic extension of $f(x, y)$. If $f(x, y)$ is not periodic, then applying \eqref{dft} introduces extra high frequency components due to sharp discontinuities at the boundaries. The central
+Equation \eqref{dft} actually gives the Fourier coefficients of the infinite periodic extension of $f(x, y)$. If $f(x, y)$ is not periodic, then applying \eqref{dft} introduces extra high frequency components due to sharp discontinuities at the boundaries. (I think this is why FFTs show the perpendicular lines running through the centre... you can apply windows to reduce this effect, but since this is qualitative I haven't bothered).
\pagebreak
\begin{center}
\pagebreak
-\section{Optical Transmission and Reflection Measurements using the VASE}
+\section{Optical Reflection Spectroscopy using the VASE}
+
+\subsection{Au on Si}
+
+\begin{figure}[H]
+ \centering
+ \includegraphics[width=0.8\textwidth]{figures/ellipsometer/au_and_blackau/au_on_si.png}
+ \caption{figure}{Reflection measurements for Au layers on Si}
+\end{figure}
+
+
+\subsection{Au on Au-Black on Au on Si}
+\begin{figure}[H]
+ \centering
+ \includegraphics[width=0.8\textwidth]{figures/ellipsometer/au_and_blackau/au_on_blackau_si.png}
+ \caption{figure}{Reflection measurements for an Au layer on Au-Black on Au layers on Si}
+\end{figure}
+
+\subsection{Comparison with model of 50nm Au on Si}
+
+\begin{figure}[H]
+ \centering
+ \includegraphics[width=0.8\textwidth]{figures/ellipsometer/au_and_blackau/generated_au_on_si_reflection.png}
+ \caption{Generated 50nm on Si}
+\end{figure}
+
+Peaks
\pagebreak
\relax
\citation{komolov}
-\@writefile{toc}{\contentsline {chapter}{\numberline {3}Experimental Techniques}{4}{chapter.3}}
+\@writefile{toc}{\contentsline {chapter}{\numberline {3}Experimental Techniques}{6}{chapter.3}}
\@writefile{lof}{\addvspace {10\p@ }}
\@writefile{lot}{\addvspace {10\p@ }}
-\@writefile{toc}{\contentsline {section}{\numberline {3.1}Total Current Spectroscopy}{4}{section.3.1}}
-\@writefile{lof}{\contentsline {figure}{\numberline {3.1}{\ignorespaces A simplified schematic of Total Current Spectroscopy Experiments \relax }}{4}{figure.3.1}}
-\newlabel{tcs_simple.pdf}{{3.1}{4}{ A simplified schematic of Total Current Spectroscopy Experiments \relax \relax }{figure.3.1}{}}
+\@writefile{toc}{\contentsline {section}{\numberline {3.1}Total Current Spectroscopy}{6}{section.3.1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {3.1}{\ignorespaces A simplified schematic of Total Current Spectroscopy Experiments \relax }}{6}{figure.3.1}}
+\newlabel{tcs_simple.pdf}{{3.1}{6}{ A simplified schematic of Total Current Spectroscopy Experiments \relax \relax }{figure.3.1}{}}
\citation{komolov}
-\@writefile{toc}{\contentsline {subsubsection}{Relationship between $S(E_1)$ and electron-surface interactions}{5}{section*.2}}
-\newlabel{tcs_theory1}{{3.1}{5}{Relationship between $S(E_1)$ and electron-surface interactions\relax }{section*.2}{}}
+\@writefile{toc}{\contentsline {subsubsection}{Relationship between $S(E_1)$ and electron-surface interactions}{7}{section*.2}}
+\newlabel{tcs_theory1}{{3.1}{7}{Relationship between $S(E_1)$ and electron-surface interactions\relax }{section*.2}{}}
\citation{komolov}
\citation{woolam1999}
\citation{woolam1999}
-\@writefile{toc}{\contentsline {section}{\numberline {3.2}Ellipsometry}{7}{section.3.2}}
-\@writefile{toc}{\contentsline {subsection}{\numberline {3.2.1}Overview}{7}{subsection.3.2.1}}
-\@writefile{lof}{\contentsline {figure}{\numberline {3.2}{\ignorespaces Diagram of an Ellipsometric Measurement \cite {woolam1999}\relax }}{7}{figure.caption.3}}
+\@writefile{toc}{\contentsline {section}{\numberline {3.2}Ellipsometry}{9}{section.3.2}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {3.2.1}Overview}{9}{subsection.3.2.1}}
+\@writefile{lof}{\contentsline {figure}{\numberline {3.2}{\ignorespaces Diagram of an Ellipsometric Measurement \cite {woolam1999}\relax }}{9}{figure.caption.3}}
\providecommand*\caption@xref[2]{\@setref\relax\@undefined{#1}}
-\newlabel{ellipsometer_measurement}{{3.2}{7}{Diagram of an Ellipsometric Measurement \cite {woolam1999}\relax \relax }{figure.caption.3}{}}
-\newlabel{ellipso}{{3.1}{7}{Overview\relax }{equation.3.2.1}{}}
+\newlabel{ellipsometer_measurement}{{3.2}{9}{Diagram of an Ellipsometric Measurement \cite {woolam1999}\relax \relax }{figure.caption.3}{}}
+\newlabel{ellipso}{{3.1}{9}{Overview\relax }{equation.3.2.1}{}}
\citation{woolam2000}
\citation{woolam2000}
\citation{oates2011}
\citation{woolam1999}
\citation{woolam1999}
-\@writefile{lof}{\contentsline {figure}{\numberline {3.3}{\ignorespaces From left to right, circular, elliptical and linearly polaristed light, viewed down the axis of beam propagation\relax }}{8}{table.caption.4}}
-\@writefile{toc}{\contentsline {subsection}{\numberline {3.2.2}Variable Angle Spectroscopic Ellipsometry}{8}{subsection.3.2.2}}
-\@writefile{lof}{\contentsline {figure}{\numberline {3.4}{\ignorespaces Block diagram of the VASE (taken from \emph {Overview of Variable Angle Spectroscopic Ellipsometry (VASE), Part I: Basic Theory and Typical Applications} \cite {woolam1999})\relax }}{9}{figure.caption.5}}
-\newlabel{ellipsometer.png}{{3.4}{9}{Block diagram of the VASE \\(taken from \emph {Overview of Variable Angle Spectroscopic Ellipsometry (VASE), Part I: Basic Theory and Typical Applications} \cite {woolam1999})\relax \relax }{figure.caption.5}{}}
-\@writefile{toc}{\contentsline {subsection}{\numberline {3.2.3}Relation of $\psi $ and $\Delta $ to properties of the sample}{9}{subsection.3.2.3}}
-\@writefile{toc}{\contentsline {subsubsection}{Bulk Substrates}{9}{section*.6}}
-\@writefile{toc}{\contentsline {subsubsection}{Single Layered Thin Films}{9}{section*.7}}
-\@writefile{toc}{\contentsline {subsubsection}{Multi-layered Thin Films}{9}{section*.8}}
-\@writefile{toc}{\contentsline {section}{\numberline {3.3}Optical Transmission and Reflection Spectroscopy}{9}{section.3.3}}
-\@writefile{toc}{\contentsline {section}{\numberline {3.4}Scanning Electron Microscopy}{9}{section.3.4}}
+\@writefile{lof}{\contentsline {figure}{\numberline {3.3}{\ignorespaces From left to right, circular, elliptical and linearly polaristed light, viewed down the axis of beam propagation\relax }}{10}{table.caption.4}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {3.2.2}Variable Angle Spectroscopic Ellipsometry}{10}{subsection.3.2.2}}
+\@writefile{lof}{\contentsline {figure}{\numberline {3.4}{\ignorespaces Block diagram of the VASE (taken from \emph {Overview of Variable Angle Spectroscopic Ellipsometry (VASE), Part I: Basic Theory and Typical Applications} \cite {woolam1999})\relax }}{11}{figure.caption.5}}
+\newlabel{ellipsometer.png}{{3.4}{11}{Block diagram of the VASE \\(taken from \emph {Overview of Variable Angle Spectroscopic Ellipsometry (VASE), Part I: Basic Theory and Typical Applications} \cite {woolam1999})\relax \relax }{figure.caption.5}{}}
+\@writefile{toc}{\contentsline {subsection}{\numberline {3.2.3}Relation of $\psi $ and $\Delta $ to properties of the sample}{11}{subsection.3.2.3}}
+\@writefile{toc}{\contentsline {subsubsection}{Bulk Substrates}{11}{section*.6}}
+\@writefile{toc}{\contentsline {subsubsection}{Single Layered Thin Films}{11}{section*.7}}
+\@writefile{toc}{\contentsline {subsubsection}{Multi-layered Thin Films}{11}{section*.8}}
+\@writefile{toc}{\contentsline {section}{\numberline {3.3}Optical Transmission and Reflection Spectroscopy}{11}{section.3.3}}
+\@writefile{toc}{\contentsline {section}{\numberline {3.4}Scanning Electron Microscopy}{11}{section.3.4}}
\@setckpt{chapters/Techniques}{
-\setcounter{page}{10}
+\setcounter{page}{12}
\setcounter{equation}{1}
-\setcounter{enumi}{0}
+\setcounter{enumi}{4}
\setcounter{enumii}{0}
\setcounter{enumiii}{0}
\setcounter{enumiv}{0}
\setcounter{ContinuedFloat}{0}
\setcounter{r@tfl@t}{0}
\setcounter{parentequation}{0}
-\setcounter{Item}{0}
+\setcounter{Item}{13}
\setcounter{Hfootnote}{4}
\setcounter{float@type}{4}
\setcounter{theorem}{0}
\@writefile{lof}{\addvspace {10\p@ }}
\@writefile{lot}{\addvspace {10\p@ }}
\@setckpt{chapters/Theory}{
-\setcounter{page}{4}
+\setcounter{page}{6}
\setcounter{equation}{0}
-\setcounter{enumi}{0}
+\setcounter{enumi}{4}
\setcounter{enumii}{0}
\setcounter{enumiii}{0}
\setcounter{enumiv}{0}
\setcounter{ContinuedFloat}{0}
\setcounter{r@tfl@t}{0}
\setcounter{parentequation}{0}
-\setcounter{Item}{0}
+\setcounter{Item}{13}
\setcounter{Hfootnote}{0}
\setcounter{float@type}{4}
\setcounter{theorem}{0}
\chapter{Overview of Theory}
+I will use this section to introduce general concepts of solid state physics. The Experimental Methods section will concentrate on the theory of each method, and how this relates to the overall theory.
+\begin{itemize}
+ \item {\bf What a nanostructured film is, how it differs from the bulk material}
+ \begin{itemize}
+ \item The surface of a solid is the interface for physical/chemical interactions with it's surrounding environment
+ \item The physical and chemical properties of a material are largely determined by the electron spectra at the surface
+ \begin{itemize}
+ \item Electron spectra is determined by the lattice potential
+ \item Characterised by
+ \begin{enumerate}
+ \item Band structure of energy states - due to periodic lattice potential
+ \item Density of States
+ \end{enumerate}
+ \item Surface differs from bulk due to
+ \begin{enumerate}
+ \item Termination of periodic lattice
+ \item Adsorbed particles on surface (thin films)
+ \item Relocation of lattice sites near the surface
+ \end{enumerate}
+ \item Band structure for Metal's vs Semi-conductors
+ \begin{enumerate}
+ \item Metals:
+ \item Semiconductors:
+ \end{enumerate}
+ \end{itemize}
+
+
+ \end{itemize}
+ \item {\bf Surface Plasmons}
+ \begin{itemize}
+ \item A collective oscillation of the electron gas in a metal
+ \item Surface plasmons are confined to the surface region; 2 dimensional, differs from bulk plasmons
+ \begin{itemize}
+ \item In nanostructured materials, plasmons can be localised
+ \end{itemize}
+ \item Bohms and Ritchie
+ \item Past studies at CAMSP and UWA
+ \item May be caused due to excitations from
+ \begin{enumerate}
+ \item Electrons - refer to next section
+ \item Photons
+ \begin{itemize}
+ \item Only light polarised in the plane of the surface can excite plasmons
+ \item Need to provide an extra wavevector to ``match'' the momenta of the photon and plasmon
+ \item Possibility for rough structure of metallic films to provide this wavevector
+ \begin{itemize}
+ \item Refer to papers on ``artificially'' blackened films
+ \item Similar topic to Nikita's thesis; look at some of his references
+ \end{itemize}
+ \end{itemize}
+ \end{enumerate}
+ \end{itemize}
+ \item {\bf Interactions between Electrons and Metallic Thin Films}
+ \begin{enumerate}
+ \item Electron-Surface Interaction
+ \begin{itemize}
+ \item How an incoming electron interacts with the surface as a whole
+ \item Elastic reflection from potential barrier
+ \item Phonon vibrations of lattice (quasi-elastic - low energy losses)
+ \end{itemize}
+ \item Electron-Electron Interaction
+ \begin{itemize}
+ \item Inelastic scattering processes determined by interaction of primary electron with the electron gas
+ \item Low energy interactions (focus of low energy TCS)
+ \begin{itemize}
+ \item Outer electron transitions between valence and conduction band (result of interaction between primary electron and an individual bound electron)
+ \item Plasmon excitation (result of interaction between incoming electron and the electron gas as a whole)
+ \end{itemize}
+ \item Higher energy interactions (focus of other forms of 2nd Electron Spectroscopy)
+ \begin{itemize}
+ \item Auger processes due to excitation of inner band electrons
+ \item ``True'' secondary electrons; bound electrons given sufficient energy to leave the surface
+ \end{itemize}
+ \end{itemize}
+ \item General structure of secondary electron energy distribution (not investigated by TCS)
+ \item Mention that secondary electrons have an angular distribution (not investigated by TCS)
+
+ \end{enumerate}
+\end{itemize}
+\chapter{Overview of Theory}
+
+
--- /dev/null
+../../../../research/ellipsometry/analysis/Au on BlackAu/generated_au_on_si_reflection.bmp
\ No newline at end of file
\bibcite{woolam2000}{10}
\bibcite{oates2011}{11}
\bibstyle{ieeetr}
-\@writefile{toc}{\contentsline {part}{References}{33}{chapter*.35}}
+\@writefile{toc}{\contentsline {part}{References}{36}{chapter*.38}}
+\@writefile{toc}{\contentsline {chapter}{\numberline {A}READ AT YOUR OWN RISK}{37}{appendix.A}}
+\@writefile{lof}{\addvspace {10\p@ }}
+\@writefile{lot}{\addvspace {10\p@ }}
\@input{appendices/tcs_noise.aux}
\@input{appendices/electron_optics.aux}
\@input{appendices/electron_gun_circuit.aux}
+\@input{appendices/data_aquisition.aux}
\BOOKMARK [1][-]{section.4.4}{Variable Angle Spectroscopy Ellipsometry}{chapter.4}
\BOOKMARK [2][-]{subsection.4.4.1}{Ag-Bright on Si substrate}{section.4.4}
\BOOKMARK [2][-]{subsection.4.4.2}{Black Ag on Si}{section.4.4}
-\BOOKMARK [1][-]{section.4.5}{Optical Transmission and Reflection Measurements using the VASE}{chapter.4}
+\BOOKMARK [1][-]{section.4.5}{Optical Reflection Spectroscopy using the VASE}{chapter.4}
+\BOOKMARK [2][-]{subsection.4.5.1}{Au on Si}{section.4.5}
+\BOOKMARK [2][-]{subsection.4.5.2}{Au on Au-Black on Au on Si}{section.4.5}
+\BOOKMARK [2][-]{subsection.4.5.3}{Comparison with model of 50nm Au on Si}{section.4.5}
\BOOKMARK [1][-]{section.4.6}{Optical Transmission Spectroscopy using OceanOptics Spectrometer}{chapter.4}
\BOOKMARK [2][-]{subsection.4.6.1}{Dark Spectrum}{section.4.6}
\BOOKMARK [2][-]{subsection.4.6.2}{Reference Spectrum}{section.4.6}
\BOOKMARK [2][-]{subsection.4.6.6}{Transmission Spectra of Ag}{section.4.6}
\BOOKMARK [2][-]{subsection.4.6.7}{Transmission Spectra of Ag and Ag-Black on Glass}{section.4.6}
\BOOKMARK [0][-]{chapter.5}{Conclusion}{}
-\BOOKMARK [-1][-]{chapter*.35}{References}{}
-\BOOKMARK [0][-]{section..1}{A two dimensional electron gun simulation}{chapter*.35}
-\BOOKMARK [1][-]{subsection..1.1}{The Ammeters}{section..1}
+\BOOKMARK [-1][-]{chapter*.38}{References}{}
+\BOOKMARK [0][-]{appendix.A}{READ AT YOUR OWN RISK}{chapter*.38}
+\BOOKMARK [1][-]{section.A.1}{Effect of Noise on the TCS Curve}{appendix.A}
+\BOOKMARK [1][-]{section.A.2}{Electron Optics}{appendix.A}
+\BOOKMARK [2][-]{subsection.A.2.1}{A two dimensional electron gun simulation}{section.A.2}
+\BOOKMARK [1][-]{section.A.3}{Electron Gun Control Circuit}{appendix.A}
+\BOOKMARK [2][-]{subsection.A.3.1}{Control Circuit}{section.A.3}
+\BOOKMARK [2][-]{subsection.A.3.2}{The Ammeters}{section.A.3}
+\BOOKMARK [1][-]{section.A.4}{Data Aquisition Hardware}{appendix.A}
+\BOOKMARK [2][-]{subsection.A.4.1}{Overview}{section.A.4}
+\BOOKMARK [2][-]{subsection.A.4.2}{Microprocessor}{section.A.4}
+\BOOKMARK [2][-]{subsection.A.4.3}{ADC Inputs}{section.A.4}
+\BOOKMARK [2][-]{subsection.A.4.4}{Temperature Measurement}{section.A.4}
+\BOOKMARK [2][-]{subsection.A.4.5}{Power Supplies}{section.A.4}
+\BOOKMARK [2][-]{subsection.A.4.6}{DAC Output}{section.A.4}
+\BOOKMARK [2][-]{subsection.A.4.7}{RS-232 Communications}{section.A.4}
% Appendices
\appendix
+\renewcommand\chaptername{Appendix}
+\chapter{READ AT YOUR OWN RISK}
+
\include{appendices/tcs_noise}
\include{appendices/electron_optics}
\include{appendices/electron_gun_circuit}
-%\include{appendices/data_aquisition}
+\include{appendices/data_aquisition}
%---------------------------------------------------------
% Appendices
\appendix
+\renewcommand\chaptername{Appendix}
+\chapter{READ AT YOUR OWN RISK}
+
+
+\include{appendices/tcs_noise}
\include{appendices/electron_optics}
\include{appendices/electron_gun_circuit}
-%\include{appendices/data_aquisition}
-\include{appendices/tcs_noise}
+\include{appendices/data_aquisition}
+
%---------------------------------------------------------
\end{document}
git.ucc.asn.au / matches / honours.git / commitdiff
UCC git Repository :: git.ucc.asn.au
