sec checkin (only small mods missing)
authorhackbard <hackbard@sage.physik.uni-augsburg.de>
Thu, 17 Jun 2010 09:20:23 +0000 (11:20 +0200)
committerhackbard <hackbard@sage.physik.uni-augsburg.de>
Thu, 17 Jun 2010 09:20:23 +0000 (11:20 +0200)
posic/talks/seminar_2010.tex

index b76a6a8..402a2c8 100644 (file)
@@ -1,6 +1,6 @@
 \pdfoutput=0
-%\documentclass[landscape,semhelv,draft]{seminar}
-\documentclass[landscape,semhelv]{seminar}
+\documentclass[landscape,semhelv,draft]{seminar}
+%\documentclass[landscape,semhelv]{seminar}
 
 \usepackage{verbatim}
 \usepackage[greek,german]{babel}
@@ -314,6 +314,19 @@ Thermal conductivity [W/cmK] & 5.0 & 4.9 & 4.9 & 1.5 & 1.3 & 22 \\
   }
   \end{minipage}
  \end{picture}
+ \begin{picture}(0,0)(-230,-35)
+ \framebox{
+ {\footnotesize\color{blue}\bf Hex: micropipes along c-axis}
+ }
+ \end{picture}
+ \begin{picture}(0,0)(-230,-10)
+ \framebox{
+ \begin{minipage}{3cm}
+ {\footnotesize\color{blue}\bf 3C-SiC fabrication\\
+                               less advanced}
+ \end{minipage}
+ }
+ \end{picture}
 
 \end{slide}
 
@@ -1971,7 +1984,7 @@ $\Longrightarrow$
 \begin{minipage}{5cm}
 Introduced C (defects)\\
 $\rightarrow$ reduction of transition point\\
-$\rightarrow$ melting even at $T_{\text{m}}$
+$\rightarrow$ melting already at $T_{\text{m}}$
 \end{minipage}
 }
 
@@ -2060,7 +2073,8 @@ y=\left(\frac{1}{2} \right)^{1/3}a_{\text{Si}}
  \item Spherical topotactically aligned precipitate\\
        $r=3.0\text{ nm}$ $\Leftrightarrow$ $\approx$ 5500 C atoms
  \item Create c-Si but skipped inside sphere of radius $x$
- \item Create 3C-SiC inside sphere of radius $x$ and lattice constant $y$
+ \item Create 3C-SiC inside sphere of radius $x$\\
+       and lattice constant $y$
  \item Strong coupling to heat bath ($T=20\,^{\circ}\mathrm{C}$)
 \end{itemize}
 \end{minipage}
@@ -2076,28 +2090,149 @@ y=\left(\frac{1}{2} \right)^{1/3}a_{\text{Si}}
  \item Slight increase of c-Si lattice constant!
  \item C-C peaks (imply same distanced Si-Si peaks)
        \begin{itemize}
-        \item New peak at 0.307 nm: NN in 3C-SiC
+        \item New peak at 0.307 nm: 2$^{\text{nd}}$ NN in 3C-SiC
         \item Bumps ({\color{green}$\downarrow$}):
               4$^{\text{th}}$ and 6$^{\text{th}}$ NN
        \end{itemize}
  \item 3C-SiC lattice constant: 4.34 \AA (bulk: 4.36 \AA)\\
        $\rightarrow$ compressed precipitate
  \item Interface tension:\\
-       20.15 eV/nm$^2$ or $3.23 \times 10^{-4}$ J/cm$^2$
+       20.15 eV/nm$^2$ or $3.23 \times 10^{-4}$ J/cm$^2$\\
+       (literature: $2 - 8 \times 10^{-4}$ J/cm$^2$)
 \end{itemize}
 \end{minipage}
 
 \end{slide}
 
+\begin{slide}
+
+ {\large\bf
+  Investigation of a silicon carbide precipitate in silicon
+ }
+
+ \footnotesize
+
+\begin{minipage}{7cm}
+\underline{Appended annealing steps}
+\begin{itemize}
+ \item artificially constructed interface\\
+       $\rightarrow$ allow for rearrangement of interface atoms
+ \item check SiC stability
+\end{itemize}
+\underline{Temperature schedule}
+\begin{itemize}
+ \item rapidly heat up structure up to $2050\,^{\circ}\mathrm{C}$\\
+       (75 K/ps)
+ \item slow heating up to $1.2\cdot T_{\text{m}}=2940\text{ K}$
+       by 1 K/ps\\
+       $\rightarrow$ melting at around 2840 K
+       (\href{../video/sic_prec_120.avi}{$\rhd$})
+ \item cooling down structure at 100 \% $T_{\text{m}}$ (1 K/ps)\\
+       $\rightarrow$ no energetically more favorable struture
+\end{itemize}
+\end{minipage}
+\begin{minipage}{6cm}
+\includegraphics[width=6.7cm]{fe_and_t_sic.ps}
+\end{minipage}
+
+\begin{minipage}{4cm}
+\includegraphics[width=4cm]{sic_prec/melt_01.eps}
+\end{minipage}
+\begin{minipage}{0.4cm}
+$\rightarrow$
+\end{minipage}
+\begin{minipage}{4cm}
+\includegraphics[width=4cm]{sic_prec/melt_02.eps}
+\end{minipage}
+\begin{minipage}{0.4cm}
+$\rightarrow$
+\end{minipage}
+\begin{minipage}{4cm}
+\includegraphics[width=4cm]{sic_prec/melt_03.eps}
+\end{minipage}
+
+\end{slide}
+
 \begin{slide}
 
  {\large\bf
   Summary / Conclusion / Outlook
  }
 
- \small
+ \scriptsize
 
+\vspace{0.1cm}
+
+\framebox{
+\begin{minipage}{12.9cm}
+ \underline{Defects}
+ \begin{itemize}
+  \item Summary \& conclusion
+        \begin{itemize}
+         \item Point defects excellently / fairly well described
+               by QM / classical potential simulations
+         \item Identified migration path explaining
+               diffusion and reorientation experiments
+         \item Agglomeration of point defects energetically favorable
+         \item C$_{\text{sub}}$ favored conditions (conceivable in IBS)
+        \end{itemize}
+  \item Todo
+        \begin{itemize}
+         \item Discussions concerning interpretation of QM results (Paderborn)
+         \item Compare migration barrier of
+               \hkl<1 1 0> Si and C-Si \hkl<1 0 0> dumbbell
+         \item Combination: Vacancy \& \hkl<1 1 0> Si self-interstitial \&
+                            C-Si \hkl<1 0 0> dumbbell (IBS)
+        \end{itemize}
+ \end{itemize}
+\end{minipage}
+}
+
+\vspace{0.2cm}
+
+\framebox{
+\begin{minipage}[t]{6.2cm}
+ \underline{Pecipitation simulations}
+ \begin{itemize}
+  \item Summary \& conclusion
+        \begin{itemize}
+         \item Low T
+               $\rightarrow$ C-Si \hkl<1 0 0> dumbbell\\
+               dominated structure
+         \item High T $\rightarrow$ C$_{\text{sub}}$ dominated structure
+         \item High C concentration\\
+               $\rightarrow$ amorphous SiC like phase
+        \end{itemize}
+  \item Todo
+        \begin{itemize}
+         \item Accelerated method: self-guided MD
+         \item Activation relaxation technique
+         \item Constrainted transition path
+        \end{itemize}
+ \end{itemize}
+\end{minipage}
+}
+\framebox{
+\begin{minipage}[t]{6.2cm}
+ \underline{Constructed 3C-SiC precipitate}
+ \begin{itemize}
+  \item Summary \& conclusion
+        \begin{itemize}
+         \item Small / stable / compressed 3C-SiC\\
+               precipitate in slightly stretched\\
+               c-Si matrix
+         \item Interface tension matches experiemnts
+        \end{itemize}
+  \item Todo
+        \begin{itemize}
+         \item Try to improve interface
+         \item Precipitates of different size
+        \end{itemize}
+ \end{itemize}
+\end{minipage}
+}
+
+ \small
 
 \end{slide}