Amorphous silicon hexaboride: a first-principles study


PHILOSOPHICAL MAGAZINE, vol.98, no.30, pp.2723-2733, 2018 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 98 Issue: 30
  • Publication Date: 2018
  • Doi Number: 10.1080/14786435.2018.1503425
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.2723-2733
  • Abdullah Gül University Affiliated: Yes


We report for the first time the atomic structure, electronic structure and mechanical properties of amorphous silicon hexaboride (a-SiB6) based on first-principles molecular dynamics simulation. The a-SiB6 model is generated from the melt and predominantly consists of pentagonal pyramid-like configurations and B-12 icosahedral molecules, similar to what has been observed in most boron-rich materials. The mean coordination number of B and Si atoms are 5.47 and 4.55, respectively. The model shows a semiconducting behaviour with a theoretical bandgap energy of 0.3eV. The conduction tail states are found to be highly localised and hence the n-type doping is suggested to be more difficult than the p-type doping for a-SiB6. The bulk modulus and Vickers hardness of a-SiB6 are estimated to be about 118 and 13-17GPa, respectively.