Monte Carlo study of magnetic properties for the mixed spin-3/2 and spin-1 ferrimagnetic nanoparticles

Based on Monte Carlo simulation, the magnetic properties of the ferrimagnetic nanoparticles on a body-centered-cubic lattice are investigated. The particle is described by a mixed-spin Heisenberg model in which S=3/2 and sigma=1 are distributed in the two interpenetrating square sublattices. It is found that no compensation point occurs at finite temperature when only the nearest-neighbor interaction between S-sigma spins is included. But, when the next-nearest-neighbor interaction between sigma-sigma spins is taken into account and exceeds a threshold value that depends on the other parameters such as the next-nearest-neighbor interaction between S-S spins and single-ion anisotropies in the Hamiltonian, a compensation point can appear. With the appropriate order parameter which is constructed to characterize the compensation behavior clearly, a variety of phase diagrams including the finite-size effect are derived and discussed. (C) 2009 Elsevier B.V. All rights reserved.