Abstrait

THEORETICAL INVESTIGATION OF THE STRUCTURAL, ELECTRONIC, ELASTIC, AND OPTICAL PROPERTIES OF ZINCBLENDE BeS UNDER HIGH PRESSURE

BadalH.Elias

A theoretical study of structural, electronic, elastic and optical properties of zinc-blende BeS under hydrostatic pressure is presented using ab-initio plane wave pseudopotential density functional theory method within the local density approximation (LDA) and generalized gradient approximation (GGA) .The dependencies of the elastic constants, the bulk modulus, young modulus and energy gaps on the applied pressure are presented, and the results are in good agreement with comparable experimental and theoretical values. Also the energy band structure and density of states under high pressure have been analysed. Furthermore, the optical constant, including the dielectric function, optical reflectivity, refractive index, optical conductivity and electron energy loss, are discussed for radiation up to 50 e V.