The high-pressure semiconducting phase of LiBC
College of Physics and Optoelectronic Technology, Nonlinear Research Institute, Baoji University of Arts and Sciences Baoji 721016, PRC
Received: 1 February 2016
Accepted: 14 April 2016
A high-pressure hexagonal semiconducting phase (space group P63mc, 2f.u./cell) of LiBC stable above 108 GPa was predicted through first-principles calculations combined with unbiased swarm structure searching techniques. This new phase consisted of three-dimensional B-C networks which originate from the dramatic out-of-plane distortions of the graphene-like B-C sublattice in the low-pressure phase under compression. Contrary to the metallizations of LiBC under high pressure previously proposed, the resulting three-dimensional B-C framework lacks the system of π bonds with mobile electrons and has more localized electrons, as a result of the semiconducting nature of this high-pressure LiBC phase.
PACS: 61.50.Ks – Crystallographic aspects of phase transformations; pressure effects / 71.15.Mb – Density functional theory, local density approximation, gradient and other corrections / 71.20.Nr – Semiconductor compounds
© EPLA, 2016