Comprehensive investigation of thermoelectric, structural, optoelectronic and magnetic properties of double perovskite Ba2BTaO6 (B = Gd, Yb) via first-principle study: a promising prospect as UV radiation reflectors

This study investigates the properties of the double perovskite compound Ba2BTaO6 (B = Gd, Yb) using the full-potential linearized augmented plane wave method (FP-LAPW) based on density functional theory (DFT) with various exchange-correlation potentials (GGA, GGA+U, and mBJ-GGA). The structural, electronic, magnetic, optical, and thermoelectric properties are explored. Ba2GdTaO6 is found to be a ferromagnetic half-semiconductor with two spin-dependent energy gaps, exhibiting stability in the ferromagnetic phase and possessing an integral magnetic moment of 7μB. On the other hand, Ba2YbTaO6 is ferrimagnetic. It shows half-metallic behavior with a semiconductor nature in the spin-up state and metallic in the spin-down state, having an integral magnetic moment of 1μB. The optical characteristics suggest their potential use in UV optoelectronic systems, including UV sensors, photodetectors, and efficient UV reflectors. Additionally, the investigated thermoelectric properties, such as the Seebeck coefficient, electrical conductivity, and Figure of merit, indicate that Ba2BTaO6 (B = Gd, Yb) materials have promising potential for practical thermoelectric applications. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.