Study of electronic and magnetic properties of MnAg layers

Self-consistent ab initio calculations, based on the density functional theory (DFT) approach and using the full potential linear augmented planewave (FLAPW) method, are performed to investigate both electronic and magnetic properties of the MnAg layers. Polarised spin and spin–orbit coupling are included in calculations within the framework of the antiferromagnetic state between two adjacent Mn layers. Magnetic moments considered to lie along axes are computed. The data obtained from the ab initio calculations are then used as input for the high-temperature series expansion (HTSE) calculations to compute other magnetic parameters. change integrals between the magnetic atoms (Mn) in the same layer and between the magnetic atoms in the bilayers adjacent are given by using mean field theory (MFT). The HTSEs of the magnetic susceptibility through Heisenberg and X Y models, for MnAg layers interacting layers, are studied to a tenth-order series in β = 1 / k B obtained for free-surface boundary conditions. The Néel temperature T N ( l ) as a function of the number of l spin layers is obtained by HTSEs of the magnetic susceptibility series by using the Padé approximant method and by MFT theory. The critical exponent γ associated with the magnetic susceptibility is deduced. The Néel temperature and the critical exponent associated with the magnetic susceptibility for MnAg are obtained.