Study of magnetic and optoelectronic properties of BaCmO3-Cubic Perovskite after the estimation of Hubbard interaction and Hund's exchange parameters: GW and DFT + U investigations

Abstract

The main objective of this work is the prediction of mechanical stability, magnetic and optoelectronic properties of BaCmO3-Cubic Perovskite by FP-(L)APW + lo method which is implemented in WIEN2k code. The structural parameters and the elastic constants were determined using GGA as exchange-correlation functional and the energy analysis of the most stable magnetic phase showed that BaCmO3 is ferromagnetic. The elastic properties confirmed the mechanical stability of this compound and by their knowledge; several related mechanical parameters were determined. This compound is based on Curium which has highly correlated electrons and since GGA semilocal functional does not accurately treat the electronic properties of this kind of compound, it has been corrected by the estimation of Hund’s exchange “J” and Hubbard interaction “U” parameters by two different methods that are Constrained DFT “cLDA” and constrained Random Phase Approximation “cRPA”. GW approximation with GGA + U as a starting point (GW@GGA + U) was also used for the prediction of the electronic properties of this compound and this choice is motivated by its proven success for this kind of study. The electronic properties have shown that BaCmO3-Cubic Perovskite is a half-metal with a total magnetic moment of ∼6 μB. The optoelectronic transitions between the valence band top and the conduction band bottom have been identified by an analysis of the real and imaginary part variations of the dielectric function.