lunch checkin (first two 100 type combos done)

diff --git a/posic/thesis/defects.tex b/posic/thesis/defects.tex
index 6299739..1b53d4e 100644 (file)
--- a/posic/thesis/defects.tex
+++ b/posic/thesis/defects.tex
@@ -735,29 +735,36 @@ The reason for nearby interstitials being favored compared to isolated ones is m
 \begin{figure}[h]
 \begin{center}
 \begin{minipage}[t]{7cm}
-a) \underline{$E=-2.25\text{ eV}$}
+a) \underline{$E_{\text{b}}=-2.25\text{ eV}$}
 \begin{center}
 \includegraphics[width=6cm]{00-1dc/2-25.eps}
 \end{center}
 \end{minipage}
 \begin{minipage}[t]{7cm}
-b) \underline{$E=-2.39\text{ eV}$}
+b) \underline{$E_{\text{b}}=-2.39\text{ eV}$}
 \begin{center}
 \includegraphics[width=6cm]{00-1dc/2-39.eps}
 \end{center}
 \end{minipage}
 \end{center}
-\caption{Relaxed structure of defect complexes consisting of two \hkl<1 0 0>-type dumbbell interstitial defects.}
+\caption{Relaxed structures of defect complexes obtained by creating a) \hkl<1 0 0> and b) \hkl<0 -1 0> dumbbels at position 1.}
 \label{fig:defects:comb_db_01}
 \end{figure}
 Figure \ref{fig:defects:comb_db_01} shows the structure of these two configurations.
-Structure b) is the energetically most favorable configuration.
-The two carbon atoms form a bond with a length of 1.38 \AA close to the nex neighbour distance in diamond or graphite, which is approximately 1.54 \AA.
-This suggests prefered C clustering as a competing mechnism to the C-Si dumbbell agglomeration inevitable for the SiC precipitation.
-Todo: Activation energy to obtain a configuration of separated C atoms again?
-However, for the second most favorable configuration, presented in figure a), the amount of possibilities for this configuration is twice as high.
-C-Si and C-C PC ...
-
+The displayed configurations are realized by creating a \hkl<1 0 0> (a)) and \hkl<0 -1 0> (b)) dumbbell at position 1.
+Structure \ref{fig:defects:comb_db_01} b) is the energetically most favorable configuration.
+After relaxation the initial configuration is still evident.
+As expected by the initialization conditions the two carbon atoms form a bond.
+This bond has a length of 1.38 \AA close to the nex neighbour distance in diamond or graphite, which is approximately 1.54 \AA.
+The minimum of binding energy observed for this configuration suggests prefered C clustering as a competing mechnism to the C-Si dumbbell interstitial agglomeration inevitable for the SiC precipitation.
+Todo: Activation energy to obtain a configuration of separated C atoms again or vice versa to obtain this configuration from separated C confs?
+However, for the second most favorable configuration, presented in figure \ref{fig:defects:comb_db_01} a), the amount of possibilities for this configuration is twice as high.
+In this configuration the two carbon atoms are spaced by 2.70 \AA.
+The initial Si (I) and C (I) dumbbell atoms are displaced along \hkl<1 0 0> and \hkl<-1 0 0> in such a way that the Si atom is forming tetrahedral bonds with two silicon and two carbon atoms.
+The carbon and silicon atom constituting the second defect are as well displaced in such a way, that the carbon atom forms tetrahedral bonds with four silicon neighbours, a configuration expected in silicon carbide.
+The Si atom numbered 2 is pushed towards the carbon atom, which results in the breaking of the bond to atom 4.
+The breaking of the $\sigma$ bond is indeed confirmed by investigating the charge density isosurface of this configuration.
+Todo: But is this configuration beneficial for SiC prec?
 
 001 at pos 2 looks as if there is no interaction.
 There is an interaction but in the same time strain is reduced due to the opposing orientations of the defects, which leads to this low energy value.