Structural, elastic, electronic, optical and thermal properties of cubic perovskite CsCdF₃ under pressure effect

¹ Département de Physique, Faculté des Sciences, Université de Sétif, 19000 Sétif, Algeria
² Département de Physique, Centre Universitaire, 34000 Bordj Bou-Arréridj, Algeria
³ Laboratoire de Physique et Mécanique des Matériaux Métalliques (LP3M), Université de Sétif, 19000 Sétif, Algeria

Corresponding author: bghebouli@yahoo.fr

Received: 17 August 2010
Revised: 12 December 2010
Accepted: 17 December 2010
Published online: 22 February 2011

Abstract

We have investigated the structural, elastic, electronic, optical and thermal properties of an insulator perovskite CsCdF₃ using the pseudo-potential plane wave (PP-PW) scheme in the frame of generalized gradient approximation (GGA) and local density approximation (LDA). The computed lattice parameter and bulk modulus agree reasonably with experimental and previous theoretical works. We find that the cubic Pm-3m crystal symmetry persists throughout the pressure range studied. The anisotropy in CsCdF₃ crystal is strong, while, by analyzing the ratio between the bulk and shear moduli, we conclude that CsCdF₃ is ductile material. The calculations reveal that CsCdF₃ is an indirect-gap insulator under ambient conditions, with the gap increasing under pressure. Also, we present the results of the densities of states and charge densities. The static dielectric constant and static refractive index are proportional to the fundamental indirect band gap Γ-R. The thermal effect on the volume, bulk modulus, heat capacities C_V and C_P and Debye temperature was predicted using the quasi-harmonic Debye model. To the author's knowledge, most of the studied properties are reported for the first time.