Structural, optoelectronic and elastic properties of quaternary perovskites CaPd3B4O12 (B = Ti, V)

Perovskites CaPd3B4O12 (B = Ti, V) are studied theoretically using generalized gradient approximation (GGA), GGA-modified Becke-Johnson (GGA-mBJ), GGA with spin-orbit coupling (GGA+SOC) and hybrid functional (HF) in the domain of density functional theory (DFT). The estimated structural parameters are reliable with the experimentally reported data. Cohesive energy and enthalpy show that these compounds are stable thermodynamically. Bonding nature makes known that the chemical bond between Ca/Ti-O is ionic, Pd/V{O is covalent and Ti/V-Ti/V is metallic. The mechanical properties show that these compounds are stable, elastically anisotropic and ductile in nature. CaPd3Ti4O12 is a 2.94 eV direct-wide bandgap semiconductor through GGA-mBJ and consistent with experiments. The optical properties show that CaPd3Ti4O12 is a good dielectric material. The dense electronic states and the wide-gap semiconductor nature of CaPd3Ti4O12 suggest that it can be used as a good thermoelectric material.