--- /dev/null
+\documentclass[semhelv]{seminar}
+
+\usepackage{verbatim}
+\usepackage[german]{babel}
+\usepackage[latin1]{inputenc}
+\usepackage[T1]{fontenc}
+\usepackage{amsmath}
+\usepackage{ae}
+
+\usepackage{calc} % Simple computations with LaTeX variables
+\usepackage[hang]{caption2} % Improved captions
+\usepackage{fancybox} % To have several backgrounds
+
+\usepackage{fancyhdr} % Headers and footers definitions
+\usepackage{fancyvrb} % Fancy verbatim environments
+\usepackage{pstcol} % PSTricks with the standard color package
+
+\usepackage{graphicx}
+\graphicspath{{./img/}}
+
+\usepackage{semcolor}
+\usepackage{semlayer} % Seminar overlays
+\usepackage{slidesec} % Seminar sections and list of slides
+
+\input{seminar.bug} % Official bugs corrections
+\input{seminar.bg2} % Unofficial bugs corrections
+
+\articlemag{1}
+
+\begin{document}
+
+\extraslideheight{10in}
+\slideframe{none}
+
+\def\slideleftmargin{.0in}
+\def\sliderightmargin{0in}
+\def\slidetopmargin{0in}
+\def\slidebottommargin{.2in} % fucking slide number gone now :)
+
+% topic
+
+\begin{slide}
+\begin{figure}[t]
+ \begin{center}
+ \includegraphics[height=1cm]{ifp.eps}
+ \\
+ \includegraphics[height=2cm]{Lehrstuhl-Logo.eps}
+ \end{center}
+\end{figure}
+\begin{center}
+ \large\bf
+ Monte Carlo simulation study of a selforganization process leading
+ to ordered precipitate structures
+\end{center}
+\begin{center}
+ F. Zirkelbach, M. H"aberlen, J. K. N. Lindner und B. Stritzker
+\end{center}
+\end{slide}
+
+% start of content
+\ptsize{8}
+
+\begin{slide}
+{\large\bf
+ Outline
+}
+\begin{picture}(300,30)
+\end{picture}
+\begin{itemize}
+ \item Cross-section TEM: selforganized $SiC_x$-precipitates
+ \item Model describing the selforganization process
+ \item Monte Carlo simulation
+ \item Comparison of experiment and simulation
+ \item Recipe for thick films of ordered laemllae
+ \item Summary
+\end{itemize}
+\end{slide}
+
+\begin{slide}
+{\large\bf
+ Cross-Section TEM image showing selforganized amorphous lamellar inclusions
+}
+\begin{figure}
+ \begin{center}
+ \includegraphics[width=10cm]{k393abild1_e.eps}
+ $180 keV \textrm{ } C^+ \rightarrow Si(100)$, $150 \, ^{\circ} \mathrm{C}$, $4.3 \times 10^{17} cm^{-2}$
+ \end{center}
+\end{figure}
+\end{slide}
+
+\begin{slide}
+{\large\bf
+ Model
+}
+\begin{figure}
+ \begin{center}
+ \includegraphics[width=8cm]{modell_ng_e.eps}
+ \end{center}
+\end{figure}
+ \scriptsize
+\begin{itemize}
+ \item Supersaturation of $C$ in $c-Si$ \\
+ $\rightarrow$ {\bf Carbon induced} nucleation of spherical $SiC_x$-precipitates
+ \item High interfacial energy between $3C-SiC$ and $c-Si$\\
+ $\rightarrow$ {\bf Amorphous} precipitates
+ \item $20 - 30\,\%$ lower silicon density of $a-SiC_x$ compared to $c-Si$\\
+ $\rightarrow$ {\bf Lateral strain} (black arrows)
+ \item Implantation range near surface\\
+ $\rightarrow$ {\bf Relaxation} of {\bf vertical strain component}
+ \item Reduction of the carbon supersaturation in $c-Si$\\
+ $\rightarrow$ {\bf Carbon diffusion} into amorphous volumina (white arrows)
+ \item Remaining lateral strain\\
+ $\rightarrow$ {\bf Strain enhanced} lateral amorphization
+ \item Absence of crystalline neighbours (structural information)\\
+ $\rightarrow$ {\bf Stabilization} of amorphous inclusions {\bf against recrystallization}
+\end{itemize}
+\end{slide}
+
+\begin{slide}
+{\large\bf
+ Simulation\\
+}
+\\
+{\bf Discretization of the target}
+\begin{center}
+ \includegraphics[width=8cm]{gitter_e.eps}
+\end{center}
+\begin{itemize}
+ \item divided into cells with a cube length of $3 \, nm$
+ \item periodic boundary conditions in $x$,$y$-direction
+\end{itemize}
+\end{slide}
+
+\begin{slide}
+{\large\bf
+ Simulation\\
+}
+{\bf TRIM collision statistics}
+\begin{center}
+ \includegraphics[width=8cm]{trim_coll_e.eps}
+\end{center}
+\begin{itemize}
+ \item identical depth profiles for
+ number of
+ collisions per depth and nuclear stopping power
+ \item mean constant energy loss per
+ collision
+\end{itemize}
+\end{slide}
+
+\begin{slide}
+{\large\bf
+ Simulation algorithm\\
+}
+\\
+The simulation algorithm consists of the following three parts looped
+$s$ times corresponding to a dose $D=s/(64\times64\times(3 \, nm)^2)$:\\
+\begin{itemize}
+ \item Amorphization / Recrystallization
+ \item Carbon incorporation
+ \item Diffusion / Sputtering
+\end{itemize}
+\end{slide}
+
+\begin{slide}
+{\large\bf
+ Amorphization / Recrystallization \\
+}
+\begin{itemize}
+ \item random numbers distributed according to the nuclear energy loss\\
+ $\rightarrow$ determine the volume in which a collision occurs
+ \item compute local probability for amorphization / recyrstallization
+ \item let another random number decide ...
+\end{itemize}
+\vspace{12pt}
+\[
+ \displaystyle p_{c \rightarrow a}(\vec r) = \textcolor[rgb]{0,1,1}{p_{b}} \qquad + \qquad \textcolor{red}{p_{c} \, c_{Carbon}(\vec r)} \qquad + \textcolor[rgb]{0.5,0.25,0.12}{\sum_{amorphous \, neighbours} \frac{p_{s} \, c_{Carbon}(\vec{r'})}{(\vec r - \vec{r'})^2}} \\
+\]
+\begin{picture}(70,15)(-10,0)
+ \bf \textcolor[rgb]{0,1,1}{normal (ballistic)}
+\end{picture}
+\begin{picture}(100,15)(-15,0)
+ \bf \textcolor{red}{carbon inuced}
+\end{picture}
+\begin{picture}(120,15)(-40,0)
+ \bf \textcolor[rgb]{0.5,0.25,0.12}{stress enhanced}
+\end{picture}
+\begin{picture}(300,40)
+$
+ p_{a \rightarrow c}(\vec r) = (1 - p_{c \rightarrow a}(\vec r)) \displaystyle \Big( 1 - \frac{\sum_{direct\, neighbours} \delta (\vec{r'})}{6} \Big) \, \textrm{, }
+$
+\end{picture}
+\vspace{6pt}
+\begin{displaymath}
+ \delta (\vec r) = \left\{ \begin{array}{ll}
+ 1 & \textrm{if volume $\vec r$ is amorphous} \\
+ 0 & \textrm{else} \\
+ \end{array} \right.
+\end{displaymath}
+\end{slide}
+
+\begin{slide}
+{\large\bf
+ Carbon incorporation
+}
+\begin{itemize}
+ \item random numbers distributed according to
+ the implantation profile to determine the
+ incorporation volume
+ \item increase the amount of carbon atoms in
+ that volume
+\end{itemize}
+\begin{picture}(50,20)(0,0)\end{picture}\\
+{\large\bf
+Diffusion/Sputtering
+}
+\begin{itemize}
+ \item every $d_v$ steps transfer of a fraction $d_r$
+ of carbon atoms from crystalline volumina to
+ an amorphous neighbour volume
+ \item remove $3 \, nm$ surface layer after $n$ loops,
+ shift remaining cells $3 \, nm$ up and insert
+ an empty, crystalline $3 \, nm$ bottom layer
+\end{itemize}
+\end{slide}
+
+\begin{slide}
+{\large\bf
+ Comparison of experiment and simulation \\
+}
+\begin{center}
+ \includegraphics[width=10cm]{dosis_entwicklung_ng_e_1-2.eps}
+\end{center}
+Simulation parameters:\\
+$p_b=0.01$, $p_c=0.001 \times (3 \, nm)^3$,
+$p_s=0.0001 \times (3 \, nm)^5$, $d_r=0.05$, $d_v=1 \times 10^6$.
+\end{slide}
+
+\begin{slide}
+{\large\bf
+ Comparison of experiment and simulation \\
+}
+\begin{center}
+ \includegraphics[width=10cm]{dosis_entwicklung_ng_e_2-2.eps}
+\end{center}
+Simulation parameters:\\
+$p_b=0.01$, $p_c=0.001 \times (3 \, nm)^3$,
+$p_s=0.0001 \times (3 \, nm)^5$, $d_r=0.05$, $d_v=1 \times 10^6$.
+\end{slide}
+
+\begin{slide}
+{\large\bf
+ Conclusion:\\
+}
+\begin{itemize}
+ \item Simulation in good agreement with experimentally observed
+ formation and growth of the continuous amorphous layer
+ \item Lamellar precipitates and their evolution at the upper
+ a/c interface with increasing dose is reproduced
+\end{itemize}
+\begin{picture}(50,20)(0,0)\end{picture}\\
+{\bf\color{red} Simulation is able to model the whole
+ depth region affected by the
+ irradiation process}
+\end{slide}
+
+\begin{slide}
+{\large\bf
+ Structural/compositional\\information \\
+}
+\begin{itemize}
+ \item Fluctuation of the carbon\\
+ concentration in the region\\
+ of the lamellae
+ \item Saturation limit of carbon\\
+ in c-$Si$ under given\\
+ implantation conditions\\
+ between $8$ and $10 \, at. \%$
+\end{itemize}
+\begin{picture}(0,0)(-145,60)
+\includegraphics[height=8cm=]{ac_cconc_ver2_e.eps}
+\end{picture}
+\end{slide}
+
+\begin{slide}
+{\large\bf
+ Structural/compositional\\information \\
+}
+\begin{itemize}
+ \item Complementarily arranged and\\
+ alternating sequence of layers\\
+ with high and low amount of\\
+ amorphous regions
+ \item Carbon accumulation in the\\
+ amorphous phase
+\end{itemize}
+\begin{picture}(0,0)(-155,60)
+\includegraphics[height=8cm]{97_98_ng_e.eps}
+\end{picture}
+\end{slide}
+
+\begin{slide}
+{\large\bf
+ Recipe for thick films of ordered lamellae \\
+}
+\\
+Prerequisites:\\
+Crystalline silicon target with a nearly constant carbon
+concentration at $10 \, at. \%$ in a $500 \, nm$ thick
+surface layer
+\includegraphics[width=8cm]{multiple_impl_cp_e.eps}
+\end{slide}
+
+\begin{slide}
+{\large\bf
+ Recipe for thick films of ordered lamellae \\
+}
+\\
+{\bf Stirring up:}
+$2 \, MeV$ $C^+$ $\rightarrow$ $Si$ irradiation step at
+$150 \, ^{\circ} \mathrm{C}$
+\begin{itemize}
+ \item This does not significantly change the carbon
+ concentration in the top $500 \, nm$
+ \item Nearly constant nuclear energy loss in the top $700 \, nm$
+ region
+\end{itemize}
+\includegraphics[width=8cm]{multiple_impl_e_ver2.eps}\\
+{\bf\color{blue} Starting point for materials showing strong photoluminescence}\\
+{\scriptsize Dihu Chen et al. Opt. Mater. 23 (2003) 65.}
+\end{slide}
+
+\begin{slide}
+{\large\bf
+ Summary
+}
+\begin{itemize}
+ \item Observation of selforganized nanometric precipitates by ion irradiation\\
+ $C \rightarrow Si \qquad T_{i}: 150 - 350 \, ^{\circ} \mathrm{C} \qquad D \le 8 \times 10^{17} cm^{-2}$
+ \item Model proposed describing the selforganization process
+ \item Model implemented in a Monte Carlo simulation code
+ \item Modelling of the complete depth region affected by the irradiation process
+ \item Simulation is able to reproduce entire amorphous phase formation
+ \item Precipitation process gets traceable by simulation
+ \item Detailed structural/compositional information available by simulation
+ \item Recipe proposed for the formation of thick films of lamellar structure
+\end{itemize}
+\end{slide}
+
+\begin{slide}
+{\large\bf
+ Thank you for your attention!\\
+ Thanks for accepting me as a guest!\\
+}
+\\
+\ldots another recipe I propose:\\
+\begin{itemize}
+ \item {\color{blue} 06 cl vodka}
+ \item {\color{blue} 03 cl peach liqueur}
+ \item {\color{blue} 03 cl amaretto}
+ \item {\color{red} 16 cl black currant juice}
+ \item {\color{red} dash of citron}
+ \item {\color{red} 3-4 ice cubes}
+\end{itemize}
+$\Rightarrow$ Killer Cool Aid
+\end{slide}
+
+\end{document}
projects / lectures / latex.git / blobdiff