Monte Carlo and Density Functional Theory investigation on the Magnetic Nature Properties of MnB2

Abstract

The magnetic properties of MnB₂ has been the subject of controversies between the experimenter and the theoretical investigations. In this paper we have rediscovered the structural, electronic and magnetic properties of MnB₂ by means of density functional theory (DFT) within the plane wave (PW) method in combination with the green function to extract the exchange coupling energy. The exchange coupling is the key input parameter to study the magnetic properties under both of the excitation of thermal energy and magnetic field in the Monte Carlo simulation. The structural optimization was performed by using Broyden-Fletcher-Goldfarb-Shanno (BFGS) approximation. The electronic and magnetic properties were determined by the analysis of density of states (DOS). The obtained results indicate that MnB₂ is a metallic material with antiferromagnetic (AFM) behavior in the ground state with Néel temperature T_N=810K. The obtained results are in good agreement with the experimental studies.