From: hackbard Date: Fri, 13 Aug 2010 14:11:01 +0000 (+0200) Subject: c_i + v and c sub X-Git-Url: https://hackdaworld.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=753820835afd003ba0fedbdff8842149bbbe10e7;p=lectures%2Flatex.git c_i + v and c sub --- diff --git a/posic/publications/defect_combos.tex b/posic/publications/defect_combos.tex index fc55378..5c86b0f 100644 --- a/posic/publications/defect_combos.tex +++ b/posic/publications/defect_combos.tex @@ -69,7 +69,8 @@ The electron-ion interaction is described by norm-conserving ultra-soft pseudopo Throughout this work an energy cut-off of \unit[300]{eV} was used to expand the wave functions into the plane-wave basis. Sampling of the Brillouin zone was restricted to the $\Gamma$-point. The defect structures and the migration paths were modelled in cubic supercells containing $216\pm2$ Si atoms. -The ions and cell shape are allowed to change in order to realize a constant pressure simulation. +The ions and cell shape were allowed to change in order to realize a constant pressure simulation. +Ionic relaxation was realized by the conjugate gradient algorithm. Spin polarization has been fully accounted for. Migration and recombination pathways have been ivestigated utilizing the constraint conjugate gradient relaxation technique (CRT)\cite{kaukonen98}. @@ -225,6 +226,7 @@ Since thermally activated C clustering is, thus, only possible by traversing ene % also: plot energy all confs with respect to C-C distance % maybe a pathway exists traversing low energy confs ?!? +% point out that configurations along 110 were extended up to the 6th NN in that direction The binding energies of the energetically most favorable configurations with the seocnd DB located along the $\langle 1 1 0\rangle$ direction and resulting C-C distances of the relaxed structures are summarized in Table~\ref{table:dc_110}. \begin{table} \begin{ruledtabular} @@ -246,13 +248,25 @@ The binding energy of these configurations with respect to the C-C distance is p \end{figure} The interaction is found to be proportional to the reciprocal cube of the C-C distance for extended separeations of the C$_{\text{i}}$ and saturates for the smallest possible separation, i.e. the ground state configuration. - -\subsection{C$_I$ next to C$_{\text{s}}$} +\subsection{C$_{\text{i}}$ next to C$_{\text{s}}$} % c_i and c_s, capaz98, mattoni2002 (restricted to 110 -110 bond chain) +\begin{table} +\begin{ruledtabular} +\begin{tabular}{l c c c c c c } + & 1 & 2 & 3 & 4 & 5 & R \\ +\hline +C$_{\text{s}}$ & 0.26 & -0.51 & -0.93 & -0.15 & 0.49 & -0.05\\ +Vacancy & -5.39 ($\rightarrow$ C$_{\text{S}}$) & -0.59 & -3.14 & -0.54 & -0.50 & -0.31 +\end{tabular} +\end{ruledtabular} +\caption{Binding energies of combinations of the C$_{\text{i}}$ $[0 0 -1]$ defect with a substitutional C or vacancy located at positions 1 to 5 according to Fig.~\ref{fig:combos}. R corresponds to the position located at $\frac{a_{\text{Si}}}{2} \langle3 2 3 \rangle$ relative to the initial defect position, which is the maximum realizable distance due to periodic boundary conditions.} +\label{table:dc_c-sv} +\end{table} +Table~\ref{table:dc_c-sv} lists the binding energies of C$_{\text{s}}$ next to the C$_{\text{i}}$ $[0 0 -1]$ DB. -\subsection{C$_I$ next to V} +\subsection{C$_{\text{i}}$ next to V} \subsection{C$_{\text{s}}$ next to Si$_{\text{i}}$}