New theoretical model on the electronic structure and magnetic properties of the YMnO3 perovskite oxide: Implementation of the U-Hubbard Hamiltonian

Abstract

Nowadays, it had been discovered that spontaneous spin polarization that increases the magnetization interest, particularly in the perovskites oxides. The First-principle calculation has played an important role in most of the modeling and simulation studies investigated. The DFT-GGA and DFT+U–GGA+U (Density Functional Theory-Generalized Gradient Approximation and the Density Functional Theory with the corrected U-Hubbard Hamiltonian–Generalized Gradient Approximation+U-Hubbard term) are introduced here to compute the YMnO3 perovskite oxide using the Wien2K code. New theoretical model on the electronic structure and the spin effect is given for the considerable oxide by investing the cubic phase. Different magnetic configurations (ferromagnetic and anti-ferromagnetic) are given for this type of structure. The implementation of the U-Hubbard term in our calculation allows more comprehension on the YMnO3 behavior and has ameliorated the obtained results. The lattice parameter of the hexagonal 4H-four layered structure is also given. We aim to compare between the two approaches employed in the present paper GGA and GGA+U, whereas we show that the (U-J) term has played the important role in the current study. The magnetic moment is also calculated using both approaches and discussed. Our results agree very well with the theoretical and experimental data. The considerable perovskite oxide exhibits the A-type anti-ferromagnetic (A-AFM) character.