From: hackbard <hackbard@sage.physik.uni-augsburg.de>
Date: Thu, 18 Feb 2010 17:30:36 +0000 (+0100)
Subject: more on defect combos .. first explanations and interpretations ...
X-Git-Url: https://hackdaworld.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5fc23f39b3d26b7d37607d3aa08faf88e582e46a;p=lectures%2Flatex.git

more on defect combos .. first explanations and interpretations ...
---

diff --git a/posic/thesis/defects.tex b/posic/thesis/defects.tex
index 5bec37f..15fe000 100644
--- a/posic/thesis/defects.tex
+++ b/posic/thesis/defects.tex
@@ -664,7 +664,7 @@ Investigations are restricted to quantum-mechanical calculations.
 \end{minipage}
 \begin{minipage}{6.0cm}
 \underline{Positions given in $a_{\text{Si}}$}\\[0.3cm]
-Initial interstitial: $\frac{1}{4}\hkl<1 1 1>$\\
+Initial interstitial I: $\frac{1}{4}\hkl<1 1 1>$\\
 Relative silicon neighbour positions:
 \begin{enumerate}
  \item $\frac{1}{4}\hkl<1 1 -1>$, $\frac{1}{4}\hkl<-1 -1 -1>$
@@ -728,14 +728,45 @@ Energies below zero indicate configurations favored compared to configurations i
 
 Investigating the first part of table \ref{tab:defects:e_of_comb}, namely the combinations with another \hkl<1 0 0>-type interstitial, most of the combinations result in energies below zero.
 Surprisingly the most favorable configurations are the ones with the second defect created at the very next silicon neighbour and a change in orientation compared to the initial one.
+This leads to the conclusion that an agglomeration of C-Si dumbbell interstitials as proposed by the precipitation model introduced in section\ref{section:assumed_prec} is indeed an energetically favored configuration of the system.
+The reason for nearby interstitials being favored compared to isolated ones is most probably the reduction of strain energy enabled by combination in contrast to the strain energy created by two individual defects.
 \begin{figure}[h]
-\caption{}
+\begin{center}
+\begin{minipage}[t]{7cm}
+a) \underline{$E=-2.25\text{ eV}$}
+\begin{center}
+\includegraphics[width=6cm]{00-1dc/2-25.eps}
+\end{center}
+\end{minipage}
+\begin{minipage}[t]{7cm}
+b) \underline{$E=-2.39\text{ eV}$}
+\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.}
 \label{fig:defects:comb_db_01}
 \end{figure}
-Figure \ref{} shows the structure of these two configurations.
+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 to each other.
+This suggests an unwanted C clustering in SiC production.
+However, for the second most favorable configuration, presented in figure a), the amount of possibilitie for this configuration is twice as high.
+Investigating C-Si and C-C bond lengths ...
 
+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.
 
+Explanation of results of defects created along <110>.
 
+-1.90 ...
 
+-2.16 ...
 
+the more far-off ones:
+-0.27 and -0.12 ...
+but better ...
+-1.88 and -1.38 ...