GGA plus U and mBJ plus U study of the optoelectronic, magnetic and thermoelectric properties of the SmAlO3 compound with spin-orbit coupling

The electronic, thermoelectric, optical, and magnetic properties of the samarium aluminate (SmAlO3) compound is studied using the spin-polarized full-potential linearized augmented plane wave (FP-LAPW) method based on the density functional theory (DFT). The exchange and correlation potential is treated with the generalized gradient approximation (GGA) and the Coulomb repulsion (U = 0.51 Ry) has been calculated theoretically and was used for the GGA+U based approximated electronic structures. Additionally, the modified Becke-Johnson (mBJ) potential was also utilized along with the GGA+U approach for the calculation of the band gap. On the other hand, the optical properties were analyzed with the mBJ+U results and the thermoelectric properties were explained on the basis of the electronic structures and density of states (DOS) with a thermoelectric efficiency of 0.66 at 300 K. The minimum reflectivity at 1.13 eV (which was equal to 1.097 mu m) was found to be in agreement with the experimental results. Further refinements in the electronic structures were obtained by adding the spin-orbit coupling (SOC) interactions to the GGA+U approach, which was then combined with the mBJ approximations. Hence, a conclusion using the combined mBJ+U+SOC study indicates that the SmAlO3 compound is a potential candidate for both thermoelectric as well as magnetic devices.