The Predicted fcc Superconducting Phase for Compressed Se and Te
ZHOU Da-Wei1**, PU Chun-Ying1, Szczęániak Dominik2,3, ZHANG Guo-Fang1, LU Cheng1, LI Gen-Quan1, SONG Jin-Fan1
1College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061 2Institute of Physics, Jan Dlugosz University in Cz?stochowa, Al. Armii Krajowej 13/15, Cz?stochowa 42200, Poland 3Institute for Molecules and Materials UMR 6283, University of Maine, Ave. Olivier Messiaen, Le Mans 72085, France
Abstract：In the framework of the ab initio random structure search method, we show that elemental Se and Te undergo pressure-induced structural transition from the bcc to fcc phase, in agreement with the theoretical results previously reported. By means of the pseudopotential plane-wave method based on density functional perturbation theory, the fcc structure for both elements is found to be another phonon-mediated superconducting phase of these materials. With a reasonable value for the Coulomb pseudopotential μ?=0.12, the maximum superconducting transition temperature Tc in the fcc phase of Se and Te is estimated to be about 5.7 K and 4.6 K, respectively. Furthermore, we show that in the entire fcc phase for Se and Te, the superconducting transition temperature decreases together with the increase in pressure, leading to the final suppression of the superconductivity. It is suggested that such behavior is mainly caused by the rapid increase in the mean-square phonon frequency ?ω2? with pressure. Finally, a very strong electron-phonon coupling value, for both Se and Te in the fcc phase, is found along the G–K high symmetry lines.
(Density functional theory, local density approximation, gradient and other corrections)
引用本文:
. [J]. 中国物理快报, 2013, 30(2): 27401-027401.
ZHOU Da-Wei, PU Chun-Ying, Szczęániak Dominik, ZHANG Guo-Fang, LU Cheng, LI Gen-Quan, SONG Jin-Fan. The Predicted fcc Superconducting Phase for Compressed Se and Te. Chin. Phys. Lett., 2013, 30(2): 27401-027401.
2013, Vol. 30 
