Monte Carlo simulation of the ising ferromagnetic iron nitride system

Using Monte Carlo methods, we investigate the magnetic properties of a mixed spin-3/2 and spin-1 Ising ferromagnetic system on an expanded FCC lattice in Fe4N. In particular, the expanded FCC lattice was divided into one simple cubic lattice composed of Fe(I) at the corner site and three inhomogeneous simple cubic lattices composed of Fe(II) at the face-centered one. The effect of the next-neighbor exchange interaction of Fe(I), the next-neighbor exchange interaction of Fe(II), and the exchange interaction of Fe(II) due to the nitrogen atoms was studied. The magnetization, internal energy and specific heat curve, and the phase diagrams are given. We found that the transition temperature and magnetic moment increase with the increase of the exchange interaction of next-nearest atoms Fe(I), Fe(II), and the exchange interaction between Fe(II) via nitrogen atoms. It is because of the exchange interaction due to the nitrogen atoms that Fe4N has a higher saturation magnetization than pure iron. (c) 2005 WILEY-VCH Verlag GmbH & Co.