Ferrimagnetic ordering behaviors and compensation temperatures in the FeIIFeIII bimetallic oxalates: Effective-field theory

A mixed spin-2 (FeІІFeІІ) and spin-5/2 (FeІІІFeІІІ) ferrimagnetic Ising model on a honeycomb lattice was built to describe the FeІІFeІІІFeІІFeІІІ bimetallic oxalates, and the ferrimagnetic ordering behaviors and compensation temperatures were investigated through the effective-field theory based on Glauber-type stochastic dynamic. It was found that the effects of the interlayer coupling and the single-ion anisotropy contributed to the increase of the critical temperature with growing layer separation and the existence of compensation temperature depending on the organic cation. In particular, the magnetization of the system may show a small discontinuous jump in a certain range of the single-ion anisotropy.