\begin{slide}
{\large\bf
- Silicon point defects
+ Cohesive energies
}
+ {\bf\color{red} From now on ...}
+
+ {\small Energies used: free energy without entropy ($\sigma \rightarrow 0$)}
+
\small
- {\color{red}\bf\LARGE
- HIER NOCH NICHT LESEN! :)\\
- }
- \begin{minipage}{6.5cm}
- <110> Si interstitial
- \begin{itemize}
- \item 2 pc's:
- $E_{\textrm{f}}=-5.47342\,\textrm{eV}$
- \item 4 pc's:
- $E_{\textrm{f}}=-5.65098\,\textrm{eV}$
- \item 32 pc's: running ...
- $E_{\textrm{f}}=\,\textrm{eV}$
- \end{itemize}
- \end{minipage}
- \begin{minipage}{6.5cm}
- plain Si
\begin{itemize}
- \item 2 pc's:
- $E_{\textrm{coh}}=-6.00846\,\textrm{eV}$
- \item 4 pc's:
- $E_{\textrm{coh}}=-5.97464\,\textrm{eV}$
- \item 32 pc's:
- $E_{\textrm{coh}}=-5.97633\,\textrm{eV}$
- \end{itemize}
- \end{minipage}\\[0.2cm]
- \begin{minipage}{6.5cm}
- hexagonal Si interstitial
- \begin{itemize}
- \item 2 pc's:
- $E_{\textrm{f}}=-5.60654\,\textrm{eV}$
- \item 4 pc's:
- $E_{\textrm{f}}=-5.60174\,\textrm{eV}$
- \item 32 pc's: running ...
- $E_{\textrm{f}}=\,\textrm{eV}$
- \end{itemize}
- tetrahedral Si interstitial
- \begin{itemize}
- \item 2 pc's: $E_{\textrm{f}}=-5.53623\,\textrm{eV}$
- \item 4 pc's: $E_{\textrm{f}}=-5.64704\,\textrm{eV}$
- \item 32 pc's: $E_{\textrm{f}}=-5.92383\,\textrm{eV}$
+ \item $E_{\textrm{free,sp}}$:
+ energy of spin polarized free atom
+ \begin{itemize}
+ \item $k$-points: Monkhorst $1\times 1\times 1$
+ \item Symmetry switched off
+ \item Spin polarized calculation
+ \item Interpolation formula according to Vosko Wilk and Nusair
+ for the correlation part of the exchange correlation functional
+ \item Gaussian smearing for the partial occupancies $f_{nk}$
+ ($\sigma=0.05$)
+ \item Magnetic mixing: AMIX = 0.2, BMIX = 0.0001
+ \item Supercell: one atom in cubic
+ $10\times 10\times 10$ \AA$^3$ box
+ \end{itemize}
+ {\color{blue}
+ $E_{\textrm{free,sp}}(\textrm{Si},250\, \textrm{eV})=
+ -0.70036911\,\textrm{eV}$
+ },
+ {\color{gray}
+ $E_{\textrm{free,sp}}(\textrm{C},xxx\, \textrm{eV})=
+ yyy\,\textrm{eV}$
+ }
+ \item $E$:
+ energy (non-polarized) of system of interest composed of\\
+ n atoms of type N, m atoms of type M, \ldots
\end{itemize}
- Si vacancy
+ \vspace*{0.3cm}
+ {\color{red}
+ \[
+ \Rightarrow
+ E_{\textrm{coh}}=\frac{
+ -\Big(E(N_nM_m\ldots)-nE_{\textrm{free,sp}}(N)-mE_{\textrm{free,sp}}(M)
+ -\ldots\Big)}
+ {n+m+\ldots}
+ \]
+ }
+
+\end{slide}
+
+\begin{slide}
+
+ {\large\bf
+ Silicon point defects\\
+ }
+
+ \small
+
+ Calculation of formation energy $E_{\textrm{f}}$
\begin{itemize}
- \item 2 pc's: $E_{\textrm{f}}=-5.65965\,\textrm{eV}$
- \item 4 pc's: $E_{\textrm{f}}=-5.56361\,\textrm{eV}$
- \item 32 pc's:$E_{\textrm{f}}=-5.92053\,\textrm{eV}$
+ \item $E_{\textrm{coh}}^{\textrm{initial conf}}$:
+ cohesive energy per atom of the initial system
+ \item $E_{\textrm{coh}}^{\textrm{interstitial conf}}$:
+ cohesive energy per atom of the interstitial system
+ \item N: amount of atoms in the interstitial system
\end{itemize}
- \end{minipage}
- \begin{minipage}{6.5cm}
+ \vspace*{0.2cm}
+ {\color{blue}
+ \[
+ \Rightarrow
+ E_{\textrm{f}}=\Big(E_{\textrm{coh}}^{\textrm{interstitial conf}}
+ -E_{\textrm{coh}}^{\textrm{initial conf}}\Big) N
+ \]
+ }
+
\begin{center}
- \includegraphics[width=6.5cm]{si_self_int.ps}
+ \includegraphics[width=7.0cm]{si_self_int.ps}
\end{center}
- \end{minipage}
\end{slide}