Phase diagrams and magnetisations of mixed spin nanoparticles with transverse field and crystal field

Abstract

ABSTRACT Using the finite cluster approximation, we investigate the phase transitions of two mixed spin 2D-nanoparticles. The effects of the crystal field and the transverse field parameters on phase diagrams and magnetisations have received the most attention. In a certain range of surface shell coupling, the model exhibits a tricritical behavior when only a longitudinal crystal field is present. The reentrance behavior may occur when the core and shell transverse fields are introduced, and the tricritical behavior may persist for appropriate values of the system parameters.