From: hackbard Date: Wed, 29 Sep 2010 15:50:50 +0000 (+0200) Subject: stupid mistakes X-Git-Url: https://hackdaworld.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7ca226503b56f40ec3c2c19414ab5625232c34fa;p=lectures%2Flatex.git stupid mistakes --- diff --git a/posic/publications/sic_prec.tex b/posic/publications/sic_prec.tex index 01f9b04..282cfcd 100644 --- a/posic/publications/sic_prec.tex +++ b/posic/publications/sic_prec.tex @@ -201,7 +201,7 @@ However, it turned out that the description fails if the EA potential is used, w In addition a different diffusion path is found to exhibit the lowest migration barrier. A C$_{\text{i}}$ \hkl[0 0 -1] DB turns into the \hkl[0 0 1] configuration at the neighbored lattice site. The transition involves the C$_{\text{i}}$ BC configuration, which, however, was found to be unstable relaxing into the C$_{\text{i}}$ \hkl<1 1 0> DB configuration. -If the migration is considered to occur within a single step, the kinetic energy of \unit[2.2]{eV} is enough to turn the \hkl<1 0 0> DB into the BC and back into a \hkl<1 0 0> DB configuration. +If the migration is considered to occur within a single step, the kinetic energy of \unit[2.2]{eV} is sufficient to turn the \hkl<1 0 0> DB into the BC and back into a \hkl<1 0 0> DB configuration. If, on the other hand, a two step process is assumed, the BC configuration will most probably relax into the C$_{\text{i}}$ \hkl<1 1 0> DB configuration resulting in different relative energies of the intermediate state and the saddle point. For the latter case a migration path, which involves a C$_{\text{i}}$ \hkl<1 1 0> DB configuration, is proposed and displayed in Fig.~\ref{fig:mig}. \begin{figure} @@ -292,9 +292,9 @@ The first noticeable and promising change observed for the Si-C bonds is the suc Obviously, sufficient kinetic energy is provided to affected atoms that are enabled to escape the cut-off region. Additionally, a more important structural change was observed, which is illustrated in the two shaded areas of the graph. Obviously, the structure obtained at \unit[450]{$^{\circ}$C}, which was found to be dominated by C$_{\text{i}}$, transforms into a C$_{\text{s}}$ dominated structure with increasing temperature. -Comparing the radial distribution at \unit[2050]{$^{\circ}$C} to the resulting bonds of C$_{\text{s}}$ in c-Si excludes any possibility of doubt. +Comparing the radial distribution at \unit[2050]{$^{\circ}$C} to the resulting bonds of C$_{\text{s}}$ in c-Si excludes all possibility of doubt. -The phase transformation is accompanied by an arising Si-Si peak at \unit[0.325]{nm}, which corresponds to the distance of next neighbored Si atoms along \hkl<1 1 0> bond chain with C$_{\text{s}}$ in between. +The phase transformation is accompanied by an arising Si-Si peak at \unit[0.325]{nm}, which corresponds to the distance of next neighbored Si atoms along the \hkl<1 1 0> bond chain with C$_{\text{s}}$ in between. Since the expected distance of these Si pairs in 3C-SiC is \unit[0.308]{nm} the existing SiC structures embedded in the c-Si host are stretched. According to the C-C radial distribution, agglomeration of C fails to appear even for elevated temperatures, as can be seen on the total amount of C pairs within the investigated separation range, which does not change significantly. @@ -337,7 +337,7 @@ The alignment of the investigated structures to the c-Si host is lost in many ca \section{Summary and discussion} -Investigations are targeted on the initially stated controversy of SiC precipitation, i.e. whether precipitation occurs abruptly after enough C$_{\text{i}}$ agglomerated or a successive agglomeration of C$_{\text{s}}$ on usual Si lattice sites (and Si$_{\text{i}}$) followed by a contraction into incoherent SiC. +Investigations are targeted at the initially stated controversy of SiC precipitation, i.e. whether precipitation occurs abruptly after enough C$_{\text{i}}$ agglomerated or after a successive agglomeration of C$_{\text{s}}$ on usual Si lattice sites (and Si$_{\text{i}}$) followed by a contraction into incoherent SiC. Results of a previous ab initio study on defects and defect combinations in C implanted Si\cite{zirkelbach10b} suggest C$_{\text{s}}$ to play a decisive role in the precipitation of SiC in Si. To support previous assumptions MD simulations, which are capable of modeling the necessary amount of atoms, i.e. the precipitate and the surrounding c-Si structure, have been employed in the current study. @@ -354,7 +354,7 @@ Incorporation into volumes $V_2$ and $V_3$ led to an amorphous SiC-like structur To compensate overestimated diffusion barriers, we performed simulations at accordingly increased temperatures. No significant change was observed for high C concentrations. The amorphous phase is maintained. -Due to the incorporation of a huge amount of C into a small volume within a short period of time damage is produced, which obviously decelerates structural evolution. +Due to the incorporation of a huge amount of C into a small volume within a short period of time, damage is produced, which obviously decelerates structural evolution. For the low C concentrations, time scales are still too low to observe C agglomeration sufficient for SiC precipitation, which is attributed to the slow phase space propagation inherent to MD in general. However, we observed a phase transition of the C$_{\text{i}}$-dominated into a clearly C$_{\text{s}}$-dominated structure. The amount of substitutionally occupied C atoms increases with increasing temperature.