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

摘要

The molecular-based magnetic materials AFe~(II)Fe~(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