+ \section*{High C concentration simulations}
+
+ {\bf Simulation sequence:}\\
+
+{\small
+ \begin{pspicture}(0,0)(30,13)
+ % nodes
+ \rput(7.5,11){\rnode{init}{\psframebox[fillstyle=solid,fillcolor=hb]{
+ \parbox{15cm}{
+ \begin{itemize}
+ \item Initial configuration: $31\times31\times31$ unit cells Si
+ \item Periodic boundary conditions
+ \item $T=450\, ^{\circ}\textrm{C}$, $p=0\text{ bar}$
+ \item Equilibration of $E_{kin}$ and $E_{pot}$
+ \end{itemize}
+ }}}}
+ \rput(7.5,5){\rnode{insert}{\psframebox[fillstyle=solid,fillcolor=lachs]{
+ \parbox{15cm}{
+ Insertion of 6000 carbon atoms at constant\\
+ temperature into $V_1$ or $V_2$ or $V_3$:
+ \begin{itemize}
+ \item Total simulation volume $V_1$
+ \item Volume of minimal 3C-SiC precipitation $V_2$
+ \item Volume of necessary amount of Si $V_3$
+ \end{itemize}
+ }}}}
+ \rput(7.5,1){\rnode{cool}{\psframebox[fillstyle=solid,fillcolor=lbb]{
+ \parbox{8cm}{
+ Cooling down to $20\, ^{\circ}\textrm{C}$
+ }}}}
+ \ncline[]{->}{init}{insert}
+ \ncline[]{->}{insert}{cool}
+ \psframe[fillstyle=solid,fillcolor=white](16,2.6)(26,12.6)
+ \psframe[fillstyle=solid,fillcolor=lightgray](18,4.6)(24,10.6)
+ \psframe[fillstyle=solid,fillcolor=gray](18.5,5.1)(23.5,10.1)
+ \rput(9,5.4){\pnode{in1}}
+ \rput(15,5.4){\pnode{in-1}}
+ \rput(17,7.2){\pnode{ins1}}
+ \rput(14,4.2){\pnode{in2}}
+ \rput(15,4.2){\pnode{in-2}}
+ \rput(18.25,6.88){\pnode{ins2}}
+ \rput(12,3.0){\pnode{in3}}
+ \rput(15,3.0){\pnode{in-3}}
+ \rput(21,7.6){\pnode{ins3}}
+ \ncline[linewidth=0.05]{->}{in-1}{ins1}
+ \ncline[linewidth=0.05]{->}{in-2}{ins2}
+ \ncline[linewidth=0.05]{->}{in-3}{ins3}
+ \ncline[linewidth=0.05]{-}{in1}{in-1}
+ \ncline[linewidth=0.05]{-}{in2}{in-2}
+ \ncline[linewidth=0.05]{-}{in3}{in-3}
+ \end{pspicture}
+}
+ {\bf Results:}\\
+ Si-C and C-C pair correlation function:\\
+ \hspace*{1.3cm} \includegraphics[width=22cm]{pc_si-c_c-c.eps}
+ \begin{center}
+ {\tiny
+ {\bf Dashed vertical lines:} Further calculated C-Si distances
+ in the \flq100\frq{} C-Si dumbbell interstitial configuration}\\[0.5cm]
+ \end{center}
+ Si-Si pair correlation function:\\
+ \hspace*{1.3cm} \includegraphics[width=22cm]{pc_si-si.eps}\\
+ {\bf Interpretation:}
+ {\small
+ \begin{itemize}
+ \item C-C peak at 0.15 nm similar to next neighbour distance of graphite
+ or diamond\\
+ $\Rightarrow$ Formation of strong C-C bonds
+ (almost only for high C concentrations)
+ \item Si-C peak at 0.19 nm similar to next neighbour distance in 3C-SiC
+ \item C-C peak at 0.31 nm equals C-C distance in 3C-SiC\\
+ (due to concatenated, differently oriented
+ \flq100\frq{} dumbbell interstitials)
+ \item Si-Si shows non-zero g(r) values around 0.31 nm like in 3C-SiC\\
+ and a decrease at regular distances\\
+ (no clear peak,
+ interval of enhanced g(r) corresponds to C-C peak width)
+ \item Low C concentration (i.e. $V_1$):
+ The \flq100\frq{} dumbbell configuration
+ \begin{itemize}
+ \item is identified to stretch the Si-Si next neighbour distance
+ to 0.3 nm
+ \item is identified to contribute to the Si-C peak at 0.19 nm
+ \item explains further C-Si peaks (dashed vertical lines)
+ \end{itemize}
+ $\Rightarrow$ C atoms are first elements arranged at distances
+ expected for 3C-SiC\\
+ $\Rightarrow$ C atoms pull the Si atoms into the right
+ configuration at a later stage
+ \item High C concentration (i.e. $V_2$ and $V_3$):
+ \begin{itemize}
+ \item High amount of damage introduced into the system
+ \item Short range order observed but almost no long range order
+ \end{itemize}
+ $\Rightarrow$ Start of amorphous SiC-like phase formation\\
+ $\Rightarrow$ Higher temperatures required for proper SiC formation
+ \end{itemize}
+ }
+