Monte Carlo calculation of Ising model with single-site anisotropy energy in ferromagnetic iron nitride system

The magnetic behavior of a mixed Ising ferromagnetic system on Fe4N expended face-center cubic lattice, with single-site anisotropy, has been studied with Monte Carlo Simulation. The expended face-center cubic 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 two sublattices have spin-3/2 and spin-1, respectively. The model includes nearest interactions and single-site anisotropy terms. By studying magnetization, internal energy, specific heat of this model at different temperatures, we found that the absolute zero value of magnetization is changed by existence of Fe(I)'s and Fe(II)'s crystal-field interactions (D1, D2). The final value of internal energy is different for different D1 and D2. Curie temperature is increasing with the increase of D1 and D2. Especially, equal point of sublattice magnetization was recognized, when D1 was changed. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)