THE DILUTE SPIN-2 ISING-MODEL - APPLICATION OF A NEW TECHNIQUE IN EFFECTIVE-FIELD THEORY

A probability distribution method based on the use of Tucker's general ised Van der Waerden identities is used in a theoretical treatment of the quenched diluted spin 2 Ising model. The approach is employed with in the framework of the single-site cluster theory based on the use of exact Ising spin identities. The variation of the transition temperat ure with site dilution is presented, and the critical concentration fo r ferromagnetic ordering is determined for the simple cubic, square an d honeycomb lattices. The temperature dependence of the magnetization, the quadrupolar moment and other higher-order moments is also present ed for selected values of site dilution.