Volume 84, Number 2, October 2008
Article Number 26003
Number of page(s) 5
Section Condensed Matter: Structural, Mechanical and Thermal Properties
Published online 25 September 2008
EPL, 84 (2008) 26003
DOI: 10.1209/0295-5075/84/26003

Phase transformation of 6H-SiC at high pressure: An ab initio constant-pressure study

S. Eker1 and M. Durandurdu1, 2

1   Fizik Bölümü, Ahi Evran Üniversitesi - Kırşehir, 40100, Turkey
2   Department of Physics, University of Texas at El Paso - El Paso, TX 79968, USA

received 24 August 2008; accepted in final form 15 September 2008; published October 2008
published online 25 September 2008

We apply a constant-pressure ab initio technique to investigate the high-pressure phase transformation of 6H-SiC and show that it transforms into a rocksalt structure. This phase change proceeds in two stages: 6H-SiC is first compressed along the c-direction and then it undergoes a shear deformation on the a-b planes. This transformation mechanism is quite similar to that of the wurtzite-to-rocksalt observed in 2H-SiC but there is no metastable phase identified along this path. The 6H-to-RS phase transition is also analyzed from the energy volume calculations. The computed transition parameters agree well with the experimental data.

64.70.K- - Solid–solid transitions. - Semiconductors.
62.50.-p - High-pressure effects in solids and liquids.

© EPLA 2008