From 1edbeb59b2db2c95de26ce475e6cc82377da1813 Mon Sep 17 00:00:00 2001 From: hackbard Date: Mon, 9 May 2011 20:57:49 +0200 Subject: [PATCH] finisched albe, go on with ensemble control --- bibdb/bibdb.bib | 15 +++++++++++++++ posic/thesis/basics.tex | 16 +++++++++++----- 2 files changed, 26 insertions(+), 5 deletions(-) diff --git a/bibdb/bibdb.bib b/bibdb/bibdb.bib index 1610f9a..c0e9159 100644 --- a/bibdb/bibdb.bib +++ b/bibdb/bibdb.bib @@ -24,6 +24,21 @@ doi = "10.1103/PhysRevB.71.035211", } +@Article{erhart04, + title = "The role of thermostats in modeling vapor phase + condensation of silicon nanoparticles", + journal = "Applied Surface Science", + volume = "226", + number = "1-3", + pages = "12--18", + year = "2004", + note = "EMRS 2003 Symposium F, Nanostructures from Clusters", + ISSN = "0169-4332", + doi = "DOI: 10.1016/j.apsusc.2003.11.003", + URL = "http://www.sciencedirect.com/science/article/B6THY-4B957HV-8/2/b35dbe80a70d173f6f7a00dacbcbd738", + author = "Paul Erhart and Karsten Albe", +} + @Article{albe2002, title = "Modeling the metal-semiconductor interaction: Analytical bond-order potential for platinum-carbon", diff --git a/posic/thesis/basics.tex b/posic/thesis/basics.tex index 1dc0df9..0e735ee 100644 --- a/posic/thesis/basics.tex +++ b/posic/thesis/basics.tex @@ -204,16 +204,22 @@ Details of the Tersoff potential derivative are presented in appendix \ref{app:d \subsubsection{Improved analytical bond order potential} Although the Tersoff potential is one of the most widely used potentials there are some shortcomings. -Describing the Si interaction Tersoff was unable to find a single parameter set to describe well both, bulk and surface properties. +Describing the Si-Si interaction Tersoff was unable to find a single parameter set to describe well both, bulk and surface properties. Due to this and since the first approach labeled T1 \cite{tersoff_si1} turned out to be unstable \cite{dodson87}, two further parametrizations exist, T2 \cite{tersoff_si2} and T3 \cite{tersoff_si3}. While T2 describes well surface properties, T3 yields improved elastic constants and should be used for describing bulk properties. However, T3, which is used in the Si/C potential, suffers from an underestimation of the dimer binding energy. -Similar behavior is found for the C interaction. +Similar behavior is found for the C-C interaction. -For this reason, Erhart and Albe provide a reparametrization of the Tersoff potential based on three independently fitted potentials for the Si-Si, C-C and Si-C interaction \cite{albe_sic_pot}. -The functional form is nearly the same like the one proposed by Tersoff. +For this reason, Erhart and Albe provide a reparametrization of the Tersoff potential based on three independently fitted parameter sets for the Si-Si, C-C and Si-C interaction \cite{albe_sic_pot}. +The functional form is similar to the one proposed by Tersoff. Differences in the energy functional and the force evaluation routine are pointed out in appendix \ref{app:d_tersoff}. -For Si ... +Concerning Si the elastic properties of the diamond phase as well as the structure and energetics of the dimer are reproduced very well. +The new parameter set for the C-C interaction yields improved dimer properties while at the same time delivers a description of the bulk phase similar to the Tersoff potential. +The potential provides succeeds in the description of the low as well as high coordinated structures is provided. +The description of elastic properties of SiC is improved with respect to the potentials available in literature. +Defect properties are only fairly reproduced but the description is comparable to previously published potentials. +It is claimed that the potential enables the modeling of widely different configurations and transitions among these and has recently been used to simulate the inert gas condensation of Si-C nanoparticles \cite{erhart04}. +Therefore the Erhart/Albe (EA) potential is considered the superior analytical bond order potential to study the SiC precipitation and associated processes in Si. \subsection{Statistical ensembles} \label{subsection:statistical_ensembles} -- 2.20.1