From: hackbard Date: Mon, 11 Apr 2011 08:42:59 +0000 (+0200) Subject: more corrections X-Git-Url: https://hackdaworld.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=471edb6f2d97040e425a18bacba8615b2e66261e;p=lectures%2Flatex.git more corrections --- diff --git a/posic/publications/defect_combos.tex b/posic/publications/defect_combos.tex index 0403fd3..7756b8d 100644 --- a/posic/publications/defect_combos.tex +++ b/posic/publications/defect_combos.tex @@ -90,7 +90,9 @@ While not guaranteed to find the true minimum energy path, the method turns out The defect formation energy $E-N_{\text{Si}}\mu_{\text{Si}}-N_{\text{C}}\mu_{\text{C}}$ is defined by choosing SiC as a particle reservoir for the C impurity, i.e. the chemical potentials are determined by the cohesive energies of a perfect Si and SiC supercell after ionic relaxation. In the same way defect formation energies are determined in the articles used for comparison. The binding energy of a defect pair is given by the difference of the formation energy of the complex and the sum of the two separated defect configurations. -Accordingly, energetically favorable configurations show binding energies below zero while non-interacting isolated defects result in a binding energy of zero. +%Accordingly, energetically favorable configurations show binding energies below zero while non-interacting isolated defects result in a binding energy of zero. +Accordingly, energetically favorable configurations result in binding energies below zero while unfavorable configurations show positive values for the binding energy. +The interaction strength, i.e. the absolute value of the binding energy, approaches zero for increasingly non-interacting isolated defects. \section{Results} @@ -495,7 +497,7 @@ Due to the low activation energy this process must be considered to be activated \end{figure} Fig.~\ref{fig:dc_si-s} shows the binding energies of pairs of C$_{\text{s}}$ and a Si$_{\text{i}}$ \hkl<1 1 0> DB with respect to the separation distance. The interaction of the defects is well approximated by a Lennard-Jones (LJ) 6-12 potential, which is used for curve fitting. -Unable to model possible positive values of the binding energy, i.e. unfavorable configurations, located to the right of the minimum, the LJ fit should rather be thought of an envelope describing the interaction strength, i.e. the absolute value of the binding energy. +Unable to model possible positive values of the binding energy, i.e. unfavorable configurations, located to the right of the minimum, the LJ fit should rather be thought as a guide for the eye describing the decrease of the interaction strength, i.e. the absolute value of the binding energy, with increasing separation distance. The binding energy quickly drops to zero. The LJ fit estimates almost zero interaction already at \unit[0.6]{nm}, indicating a low interaction capture radius of the defect pair. In IBS highly energetic collisions are assumed to easily produce configurations of defects exhibiting separation distances exceeding the capture radius.