FIZIKA A 14 (2005)  3, 245 - 254

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STRUCTURAL AND ELECTRONIC PROPERTIES OF bcc SELENIUM UNDER HIGH PRESSURE

FOUAD EL HAJ HASSANa, MOUHAMED ZOAETER and ABBAS HIJAZI
aE-mail address: hassan.f@ul.edu.lb

Université libanaise, Faculté des sciences (I), Laboratoire de physique de matériaux (LPM), Elhadath, Beirut, Lebanon

Received 25 August 2004; revised manuscript received 15 February 2005
Accepted 6 June 2005     Online 6 February 2006

Full-potential linearized augmented plane-wave method (FP-LAPW) within the density functional theory is applied to study the structural and electronic properties of selenium in the bcc phase at high pressures. We used local density approximation with and without generalized gradient correction based on exchange-correlation energy optimization. We have determined the full set of first-order elastic constants, which have not been established earlier experimentally or theoretically. The elastic moduli show linear dependence on pressure. The calculated energy allowed us to investigate several structural properties such as lattice parameter, bulk modulus and its pressure derivative. Our calculated lattice parameter is found to be in reasonable agreement with experimental result. The electronic band structure and the density of states at various pressures are also calculated to show that there is a possibility for these compounds to become metallic at high pressures. Further, we have calculated the electronic specific heat coefficient, which decreases with the increase of pressure.

PACS numbers: 62.20.Dc, 71.15.Mb, 71.15.-m, 71.15.Nc, 71.20.-b
UDC 539.3

Keywords: selenium, FP-LAPW, high pressure, bcc phase, elastic constant, band structure, density of states

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