Effects of Transverse Field on Internal Energy and Specific Heat of a Molecular-Based Materials

The molecular-based magnetic materials AFe^IIFe^III (C₂O₄)₃ have ahoneycomb structure in which Fe^III (S=2) and Fe^III (S=5/2) occupy sites alternately. They can be described as mixed spin-2 and spin-5/2 Ising model with ferrimagnetic interlayer coupling. The influences of the transversefield on the internal energy and the specific heat of the molecular-based magnetic system have been studied numerically by using the effective-field theory with self-spin correlations and the differential operator technique.