An Insight into the Electronic and Optical Characteristics of BaCu2As2 and α-BaCu2Sb2 Compounds: An Ab Initio Study
Abstract
This report presents the first principle calculations of the electronic and optical characteristics of BaCu2As2 and α-BaCu2Sb2 metallic compounds. The full potential linear augmented plane-wave (FPLAPW) technique is the basis for these computations. The exchange-correlation energy involves the contributions from the local density approximation (LDA), generalized gradient approximation (GGA) and Engel-Vosko generalized gradient approximation (EVGGA). As the EVGGA show better band splitting comparing to LDA and GGA therefore, we show the results of this approximation. The computed electronic band structures illustrate metallic nature of these compounds due to band’s overlapping at the Fermi energy. The electronic density of states (total and partial DOS) of these compounds reveal that there exists strong hybridization between As/Sb-p and Cu-d states, with weak hybridization between Ba-s and Cu-s states and also between Cu-d and As-d states below the Fermi level (EF). The As/Sb-p and Ba-d states contribute predominantly to the DOS at and above EF. The origin of different features of optical properties are discussed based on band structure. The α-BaCu2Sb2 compound demonstrates improved behavior in reflectivity as compared to that of BaCu2As2 compound. Due to this fact, the ability of reflecting solar light in α-BaCu2Sb2 compound is more robust than that of BaCu2As2.