From: hackbard Date: Thu, 7 Oct 2010 16:45:54 +0000 (+0200) Subject: parts of si tet c sub X-Git-Url: https://hackdaworld.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=79c07d5de9e456cfa1fb09dba335ed565835bcc5;p=lectures%2Flatex.git parts of si tet c sub --- diff --git a/posic/publications/sic_prec.tex b/posic/publications/sic_prec.tex index a8d3433..96f979c 100644 --- a/posic/publications/sic_prec.tex +++ b/posic/publications/sic_prec.tex @@ -179,7 +179,7 @@ Results of VASP and EA calculations are summarized in Table~\ref{tab:defect_comb \begin{tabular}{l c c c} & C$_{\text{i}}$ \hkl<1 0 0> & C$_{\text{s}}$ \& Si$_{\text{i}}$ \hkl<1 1 0> & C$_{\text{s}}$ \& Si$_{\text{i}}$ T\\ \hline - VASP & 3.72 & 4.37 & - \\ + VASP & 3.72 & 4.37 & 4.17$^{\text{a}}$/4.99$^{\text{b}}$/4.96$^{\text{c}}$ \\ Erhart/Albe & 3.88 & 4.93 & 5.25$^{\text{a}}$/5.08$^{\text{b}}$/4.43$^{\text{c}}$ \end{tabular} \end{ruledtabular} @@ -192,6 +192,10 @@ With increasing separation distance the energies of formation decrease. However, even for non-interacting defects, the energy of formation, which is then given by the sum of the formation energies of the separated defects (\unit[4.15]{eV}) is still higher than that of the C$_{\text{i}}$ \hkl<1 0 0> DB. Unexpectedly, the structure of a Si$_{\text{i}}$ \hkl<1 1 0> DB and a neighbored C$_{\text{s}}$, which is the most favored configuration of C$_{\text{s}}$ and Si$_{\text{i}}$ according to quantum-mechanical calculations\cite{zirkelbach10b}, likewise constitutes an energetically favorable configuration within the EA description, which is even preferred over the two least separated configurations of C$_{\text{s}}$ and Si$_{\text{i}}$ T. This is attributed to an effective reduction in strain enabled by the respective combination. +Quantum-mechanical results reveal a more favorable energy of fomation for configuration a of C$_{\text{s}}$ and Si$_{\text{i}}$ T. +However, this involves a structural transition into the C$_{\text{i}}$ \hkl<1 1 0> interstitial, thus, not maintaining the tetrahedral Si nor the substitutional C defect. +%qm results show smaller energies for the a type of si tet + c sub, however this involves structural change towards the 110 DB not maintaining tetrahedral nor the substitutional defect. +% in anyways, no configurations more favorable than c-si DB arise. Thus, a proper description with respect to the relative energies of formation is assumed for the EA potential. \subsection{Carbon mobility} @@ -335,6 +339,14 @@ Fig.~\ref{fig:v2} displays the radial distribution for high C concentrations. \caption{Radial distribution function for Si-C (Fig.~\ref{fig:v2:si-c}) and C-C (Fig.~\ref{fig:v2:c-c}) pairs for the C insertion into $V_2$ at elevated temperatures. Arrows mark the respective cut-off distances.} \label{fig:v2} \end{figure} +\begin{figure} +\begin{center} +\includegraphics[width=\columnwidth]{../img/plot.eps} +\end{center} +\caption{Cross section along the \hkl(1 -1 0) plane of the atomic structure of the high concentration simulation for a C insertion temperature of \unit[2050]{$^{\circ}$C}.} +\label{fig:v2as} +\end{figure} +A cross-section along the \hkl(1 -1 0) plane of the atomic structure for a C insertion temperature of \unit[2050]{$^{\circ}$C} is shown in Fig.~\ref{fig:v2as}. The amorphous SiC-like phase remains. No significant change in structure is observed. However, the decrease of the cut-off artifact and slightly sharper peaks observed with increasing temperature, in turn, indicate a slight acceleration of the dynamics realized by the supply of kinetic energy.