Multilayer transition in a spin 3/2 Blume–Capel model with RKKY interaction

Using Monte Carlo simulation and mean-field theory, we have studied the effect of RKKY interaction on the multi-layer transition and magnetic properties of a spin-3/2 Blume–Capel model of a system formed by two magnetic multi-layer materials, of different thicknesses, separated by a non-magnetic spacer of thickness M. It is found that the multi-layer magnetic order–disorder transition temperature depends strongly on the thicknesses of the magnetic layer and the non-magnetic layer. The transition temperature increases with increasing thickness of the magnetic multi-layers and decreases with increasing thickness of the non-magnetic one. Furthermore, there exists a critical thickness ML of the non-magnetic spacer beyond which the effect of the RKKY interaction becomes negligible and separate transitions occur in the two magnetic layers. The critical thickness ML decreases on increasing the magnetic crystal field and/or the Fermi level kf. Moreover, the multi-layer transition temperature undergoes oscillations as a function of the Fermi level. The susceptibility critical exponents are computed within Monte Carlo simulations.