Decoupling approximation in spin-S (S 1/2) Ising systems

A decoupling approximation is introduced for studying the magnetic properties of a spin-S (S 1/2) Ising system within the framework of the differential operator technique. The formulation yields a statistical accuracy better than that of Bethe–Peierls approximation. It is also applied to the study of phase diagram in a spin-S transverse Ising system.