A NOTE ON A FERRIMAGNETIC ISING SYSTEM WITH DECORATED MAGNETIC AND NONMAGNETIC ATOMS

The transition temperature T-C of a spin-1/2 Ising system in which the middle point of each bond is decorated randomly by a spin-S (S > 1/2) or non-magnetic atom is investigated on the basis of the new formulat ion in the effective-field theory with correlations. The numerical res ults are given for the square lattice. Different features are found fo r the behavior of Te in the diluted system with a negative crystal-fie ld interaction constant on a spin-S atom, depending on whether S is an integer or a half-integer.