Investigation of the Physical Attributes of Sr2GeCrO6, Sr2MgMoO6, Ba2MgMoO6, Ba2ZnMoO6, and Ba2HgWO6 Double Perovskite Oxides

A density functional theory-based study on the physical properties of significant double perovskite oxides Sr₂GeCrO₆, Sr₂MgMoO₆, Ba₂MgMoO₆, Ba₂ZnMoO₆, and Ba₂HgWO₆ has been conducted using the Vienna Ab initio Simulation Package and WIEN2K code. Structural analysis reveals the simple cubic crystal structure of double perovskite oxides. Phonon properties indicate the dynamical stability of Sr₂GeCrO₆, Ba₂MgMoO₆, and Ba₂ZnMoO₆ compounds. The band structure analysis indicates the metallic character of Sr₂GeCrO₆. However, generalized gradient approximation of Perdew–Burke–Ernzerhof and modified Becke–Johnson both suggest the indirect semiconducting nature of Ba₂MgMoO₆ and Ba₂ZnMoO₆. The crystal orbital Hamilton population (–COHP) examination evidences the strongest bonding interactions of O–Ba in these perovskite oxides. Both Ba₂MgMoO₆ and Ba₂ZnMoO₆ compounds exhibit p-type character, as indicated by the partial charge density distributions in the highest occupied molecular orbital and lowest unoccupied molecular orbital (LUMO) orbitals, which govern the band edges near Fermi level. LUMO orbitals are located on Mo and O atoms and are composed of heteronuclear s- and p-type interactions. The investigation comprehensively analyzes calculated optoelectronic properties, including complex dielectric function, optical conductivity, loss function, refractive index, and so on. These parameters are examined in detail, offering profound insights into the materials’ optical and electronic characteristics.