Novel 122-type Ir-based superconductors BaIr2Mi2 (Mi = P and As): A density functional study

Abstract

We explore the structural, electronic, bonding, mechanical, thermodynamic and superconducting properties of two newly discovered isostructural bulk superconductors barium iridium phosphide BaIr2P2 (Tc ~ 2.1 K) and barium iridium arsenide BaIr2As2 (Tc ~ 2.45 K). The optimized structural parameters of both the compounds show good agreement with the experimentally evaluated values. The replacement of P by As mostly affects the c value, whereas a remains approximately the same. Metallic conductivity is observed for both the superconductors. The analysis of DOS, Mulliken atomic populations and total charge density revel a complex bonding in BaIr2P2 and BaIr2As2 with ionic, covalent and metallic characteristics. Mechanical and dynamical stability of both the phases is confirmed by analyzing the elastic constant data.