Magnetic behaviors of diatomic molecules with mixed spin-1 and spin-1/2 on the Bethe lattice

It is considered that each Bethe lattice (BL) site is inhabited by a diatomic molecule made up of either two spin -1/2 or two spin -1 atoms, respectively. Then, each diatomic molecule is thought to interact with others via its atoms in terms of numerous bilinear interaction parameters, such as the interaction of atoms within each molecule and the interaction of atoms between molecules. The thermal fluctuations of magnetizations for the diatomic molecule are examined by incorporating a crystal field for the spin -1 atoms and mapping their magnetic phase diagrams on the BL with coordination number q = 3 using exact recursion relations (ERR). The effects of the external magnetic field are also taken into account while analyzing the thermal fluctuations in magnetizations. For various antiferromagnetic (AFM) and ferromagnetic (FM) interaction setups, the model always presents second- and first -order phase lines merging at a tricritical point (TCP). The acquired results are compared to those of a BL, in which each site is associated with only one atom.