Magnetic properties of a molecular-based magnet AFe~ⅡFe~Ⅲ(C_2O_4)_3 with biaxial crystal field

摘要

The molecular-based magnetic materials AFe~ⅡFe~Ⅲ(C_2O_4)_3 have a honeycomb structure in which Fe~Ⅱ(S=2) and Fe~Ⅲ(S=5/2) occupy sites alternately, which is described by mixed spin-2 and spin-5/2 Ising model with ferrimagnetic interlayer coupling. Within the effective-field theory with self-spin correlations, the effects of the biaxial crystal field on the magnetization, initial susceptibility, and internal energy of this molecular-based system have been studied numerically.