Investigating electronic and optical properties of pyrochlore oxides Ta2A2O7 (A = Cd and Ge) for promising optoelectronic applications

Abstract

Due to their stable crystal structure and controllable lattice parameters, rare earth zirconates with pyrochlore type structures have demonstrated a promise for usage in practical applications. We have investigated the electronic and optical properties of pyrochlore oxide compound named Ta2A2O7 (A = Cd and Ge) using density functional theory based on spin–orbit coupling and Hubbard (SOC + U) corrections to consider the existence electronic d orbitals of (A) and f elements (Ta). This study focuses on the characterization and investigation of pyrochlore oxides with the A2B2O7 composition, which have significant technological applications including quantum spin ices, solid oxide fuel cells, and nuclear waste forms. No evidence regarding magnetic moment is obtained from the first run with spin-polarization setup. Also, from the spectra of TDOS was showing a similar overall profile for both spin channels. The electronic properties (total and partial) densities of states as well as the optical properties such as the complex dielectric function, refractive index, absorption coefficient and reflectivity for wavelengths in the visible spectrum have been reported to explore the potential use of these compounds in technological applications. Consequently, the investigated compounds can be used in optoelectronic device fabrication.