A note on a ferrimagnetic Ising system with decorated magnetic and non-magnetic atoms

The transition temperature Tc of a Ising system in which the middle point of each bond is decorated randomly by a spin-S ( ) or non-magnetic atom is investigated on the basis of the new formulation in the effective-field theory with correlations. The numerical results are given for the square lattice. Different features are found for the behavior of Tc in the diluted system with a negative crystal-field interaction constant on a spin-S atom, depending on whether S is an integer or a half-integer.