safety commit + new sic prec sequence figures

[lectures/latex.git] / posic / talks / dpg_2008.tex

diff --git a/posic/talks/dpg_2008.tex b/posic/talks/dpg_2008.tex
index 00e9aaf..5bc70e6 100644 (file)
--- a/posic/talks/dpg_2008.tex
+++ b/posic/talks/dpg_2008.tex
@@ -28,6 +28,8 @@
 
 \articlemag{1}
 
+\special{landscape}
+
 \begin{document}
 
 \extraslideheight{10in}
@@ -132,8 +134,8 @@
        \end{itemize}
   \item Results gained by simulation
         \begin{itemize}
-         \item Carbon interstitials in silicon
-         \item Existence of $SiC$-precipitates
+         \item Interstitials in silicon
+         \item $SiC$-precipitation experiments
        \end{itemize}
   \item Conclusion / Outlook
  \end{itemize}
@@ -141,5 +143,185 @@
 
 % start of contents
 
+\begin{slide}
+
+ {\large\bf
+  Motivation / Introduction
+ }
+
+ \small
+ \vspace{6pt}
+
+ Supposed mechanism of the conversion of heavily carbon doped Si into SiC:
+
+ \vspace{8pt}
+
+ \begin{minipage}{3.8cm}
+ \includegraphics[width=3.7cm]{sic_prec_seq_01.eps}
+ \end{minipage}
+ \hspace{0.6cm}
+ \begin{minipage}{3.8cm}
+ \includegraphics[width=3.7cm]{sic_prec_seq_02.eps}
+ \end{minipage}
+ \hspace{0.6cm}
+ \begin{minipage}{3.8cm}
+ \includegraphics[width=3.7cm]{sic_prec_seq_03.eps}
+ \end{minipage}
+
+ \vspace{8pt}
+
+ \begin{minipage}{3.8cm}
+ Formation of C-Si dumbbells on regular c-Si lattice sites
+ \end{minipage}
+ \hspace{0.6cm}
+ \begin{minipage}{3.8cm}
+ Agglomeration into large clusters (embryos)\\
+ \end{minipage}
+ \hspace{0.6cm}
+ \begin{minipage}{3.8cm}
+ Precipitation of 3C-SiC + Creation of interstitials\\
+ \end{minipage}
+
+ \begin{center}
+ \[5a_{SiC}=4a_{Si} \quad \Rightarrow \quad
+   \frac{n_{SiC}}{n_{Si}}=\frac{\frac{4}{a_{SiC}^3}}{\frac{8}{a_{Si}^3}}=
+                          \frac{5^3}{2\cdot4^3}=97,66\%
+ \]
+ \end{center}
+
+ Experimentally observed minimal diameter of precipitation: 4 - 5 nm
+
+\end{slide}
+
+\begin{slide}
+
+ {\large\bf
+  Simulation details
+ }
+
+ MD basics:
+ \begin{itemize}
+  \item Microscopic description of N particle system
+  \item Analytical interaction potential
+  \item Hamilton's equations of motion as propagation rule\\
+        in 6N-dimemnsional phase space
+  \item Observables obtained by time average
+ \end{itemize}
+
+ \vspace{4pt}
+
+ Application details:
+ \begin{itemize}
+  \item Integrator: velocity verlet, timestep: $1\, fs$
+  \item Ensemble control: NVT, Berendsen thermostat, $\tau=100.0$
+  \item Potential: Tersoff-like bond order potential\\
+        \[
+       E = \frac{1}{2} \sum_{i \neq j} \pot_{ij}, \quad
+       \pot_{ij} = f_C(r_{ij}) \left[ f_R(r_{ij}) + b_{ij} f_A(r_{ij}) \right]
+       \]
+       \begin{center}
+        {\scriptsize P. Erhart und K. Albe. Phys. Rev. B 71 (2005) 035211}
+       \end{center}
+ \end{itemize}
+
+\end{slide}
+
+\begin{slide}
+
+ {\large\bf
+  Simulation details
+ }
+
+ Interstitial experiments:
+ \begin{itemize}
+  \item Initial configuration: $9\times9\times9$ unit cells Si
+  \item Periodic boundary conditions
+  \item $T=0 \, K$
+  \item Insertion of Si / C atom at
+        \begin{itemize}
+         \item $(0,0,0)$ (tetrahedral)
+         \item $(-1/8,-1/8,1/8)$ (hexagonal)
+         \item $(-1/8,-1/8,-1/4)$, $(-1/4,-1/4,-1/4)$ (110 dumbbell)
+        \item random positions (critical distance check)
+       \end{itemize}
+  \item Relaxation time: $2\, ps$
+ \end{itemize}
+
+\end{slide}
+
+\begin{slide}
+
+ {\large\bf
+  Simulation details
+ }
+
+ SiC precipitation experiments:
+ \begin{itemize}
+  \item Initial configuration: $31\times31\times31$ unit cells Si
+  \item Periodic boundary conditions
+  \item $T=450\, ^{\circ}C$
+  \item Steady state time: $600\, fs$
+  \item C insertion steps:
+        \begin{itemize}
+        \item If $T=450\pm 1\, ^{\circ}C$:\\
+              Insertion of 10 atoms at random positions within $V_{ins}$
+        \item Otherwise: Annealing for another $100\, fs$
+       \end{itemize}
+  \item Annealing: ($T_a: 450\rightarrow 20 \, ^{\circ}C$)
+        \begin{itemize}
+        \item If $T=T_a$: Decrease $T_a$ by $1\, ^{\circ}C$
+        \item Otherwise: Annealing for another $50\, fs$
+       \end{itemize}
+ \end{itemize}
+
+ 3 szenarios
+ \begin{itemize}
+  \item $V_ins$: total volume $V$
+  \item $V_ins$: 
+ \end{itemize}
+
+\end{slide}
+
+\begin{slide}
+
+ {\large\bf
+  Results
+ }
+
+\end{slide}
+
+\begin{slide}
+
+ {\large\bf
+  Results
+ }
+
+\end{slide}
+
+\begin{slide}
+
+ {\large\bf
+  Results
+ }
+
+\end{slide}
+
+\begin{slide}
+
+ {\large\bf
+  Results
+ }
+
+\end{slide}
+
+\begin{slide}
+
+ {\large\bf
+  Conclusion / Outlook
+ }
+
+\end{slide}
+
+
 \end{document}