started min e along 110

diff --git a/posic/thesis/defects.tex b/posic/thesis/defects.tex
index 16868a0..a639609 100644 (file)
--- a/posic/thesis/defects.tex
+++ b/posic/thesis/defects.tex
@@ -863,20 +863,36 @@ The upper dumbbell atoms are pushed towards each other forming fourfold coordina
 While the displacements of the silicon atoms in case b) are symmetric to the \hkl(1 1 0) plane, in case a) the silicon atom of the initial dumbbel is pushed a little further in the direction of the carbon atom of the second dumbbell than the carbon atom is pushed towards the silicon atom.
 The bottom atoms of the dumbbells remain in threefold coordination.
 The symmetric configuration is energetically more favorable ($E_{\text{b}}=-1.66\text{ eV}$) since the displacements of the atoms is less than in the antiparallel case ($E_{\text{b}}=-1.53\text{ eV}$).
+In figure \ref{fig:defects:comb_db_05} c) and d) the nonparallel orientations, namely the \hkl<0 -1 0> and \hkl<1 0 0> dumbbells are shown.
+Binding energies of -1.88 eV and -1.38 eV are obtained for the relaxed structures.
+In both cases the silicon atom of the initial interstitial is pulled towards the near by atom of the second dumbbell so that both atoms form fourfold coordinated bonds to their next neighbours.
+In case c) it is the carbon and in case d) the silicon atom of the second interstitial to form the additional bond with the silicon atom of the initial interstitial.
+The atom of the second dumbbell, the carbon atom of the initial dumbbell and the two interconnecting silicon atoms again reside in a plane.
+A typical C-C distance of 2.79 \AA{} is, thus, observed for case c).
+The far-off atom of the second dumbbell resides in threefold coordination.
+
+Assuming that it is possible for the system to minimize free energy by reorientation of the dumbbell in any position ... we now give the minimum energies of dumbbells alomg the \hkl<1 1 0> direction ...
+\begin{table}[h]
+\begin{center}
+\begin{tabular}{l c c c c c c}
+\hline
+\hline
+ & 1 & 2 & 3 & 4 & 5 & 6\\
+\hline
+$E_{\text{b}}$ [eV] & -2.39 & -1.88 & -0.59 & -0.31 & - & - \\
+Type & \hkl<-1 0 0> & \hkl<1 0 0> & \hkl<1 0 0> & \hkl<1 0 0> & \hkl<> & \hkl<> \\
+\hline
+\hline
+\end{tabular}
+\end{center}
+\caption{Binding energy and type of the minimum energy configuration of an additional dumbbell with respect to the separation distance in bonds along the \hkl<1 1 0> direction.}
+\label{tab:defects:comb_db110}
+\end{table}
 
-... typical C-C distance 2.79 \AA ...
-
-I
-but better ...
--1.88 and -1.38 ...
--1.38: Si (I) moves towards 2nd Si int in 110 direction, such that both Si 4fold coordinated and C remain 3fold ...
--1.88: threefold coordinated c atoms but all participating Si atoms fourfold coordinated ...
-
-Explanation of results of defects created along <110>.
-
-Minimum E (reorientation) per distance
+Todo: DB mig along 110?
 
 Todo: Si int and C sub ...
+
 Todo: Model of kick-out and kick-in mechnism?
 
 Todo: Jahn-Teller distortion (vacancy) $\rightarrow$ actually three possibilities! :(