A Tight-Binding Molecular-Dynamics Approach to Structural and Electronic Properties of a-SiC

  • V. I. Ivashchenko
  • P. E. A. Turchi
  • V. I. Shevchenko
Chapter
Part of the NATO Science Series book series (NAII, volume 102)

Abstract

There have been a few theoretical studies addressing the topological structure, electronic distribution in amorphous silicon carbide (a-SiC) [1, 2, 3, 4, 5, 6]. These studies have involved molecular dynamics (MD) simulations in combination with an ab initio pseudo-potential approach (PA) in the local density approximation (LDA) for exchange and correlation interactions among valence electrons [1, 2, 3], Monte Carlo calculations within the Tersoff empirical potential (TEP) formalism [4, 5] and MD simulations based on the TEP [6]. The densities of states (DOS), computed for small super-cells using the PA, do not show a distinct semiconducting band gap (BG), though the DOS of the 54-atom sample [1] has the distinct dip demonstrating the trend towards gap formation. Electronic states in large sized a-SiC samples were carefully investigated in the framework of a sp3s* tight-binding (TB) scheme [6]. However, the latter investigation is inconsistent, since by generating a-SiC samples the scheme was not involved. The first-principles PA makes it possible to obtain accurately the atomic distribution in a-SiC but electronic states are computed incorrectly, since the LDA is known to underestimate the BG [2,7]. Therefore, it is rewarding to study both the atomic and electronic structures of a-SiC using another procedures capable to provide the appropriate atomic distribution and to describe the electronic states in the BG region in the framework of the same approach.

Keywords

Entropy Graphite Carbide Gallium Arsenide 

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Copyright information

© Springer Science+Business Media Dordrecht 2003

Authors and Affiliations

  • V. I. Ivashchenko
    • 1
  • P. E. A. Turchi
    • 2
  • V. I. Shevchenko
    • 1
  1. 1.Institute of Problems of Material ScienceNAS of UkraineKyivUkraine
  2. 2.Lawrence Livermore National Laboratory (L-353)LivermoreUSA

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