Investigation of Electronic and Magnetic Properties of Iron(II)-Bromide Compound by First Principle, Mean Field, Series Expansion Calculations and Monte Carlo Simulation

The self-consistent abinitio calculations, based on DFT (density functional theory) approach and using FLAPW (full-potential linear augmented plane wave) method, are performed to investigate both electronic and magnetic properties of the FeBr 2 compound. Polarized spin and spin-orbit coupling are included in calculations within the framework of the ferromagnetic state between two adjacent Fe atoms. Magnetic moments considered to lie along (001) axes are computed. The antiferromagnetic and ferromagnetic energies of FeBr 2 are estimated. Obtained data from abinitio calculations are used as input for the high-temperature series expansion (HTSE) calculations to compute other magnetic parameters. The exchange interactions between the magnetic atoms Fe–Fe in FeBr 2 are established by using the mean field theory. The critical temperature TC(K) is obtained by HTSEs combined with the Padé approximant method. The critical exponent γ associated with the magnetic susceptibility is established. The critical temperature and magnetic hysteresis cycle are obtained by Monte Carlo simulation.