A UNIFIED EFFECTIVE-FIELD RENORMALIZATION-GROUP FRAMEWORK APPROACH FOR THE QUENCHED DILUTED ISING-MODELS

A unified effective-field renormalization-group framework (EFRG) for b oth quenched bond- and site-diluted Ising models is herein developed b y extending recent works. The method, as in the previous works, follow s up the same strategy of the mean-field renormalization-group scheme (MFRG), and is achieved by introducing an alternative way for construc ting classical effective-field equations of state, based on rigorous I sing spin identities. The concentration dependence of the critical tem perature, T(c)(p), and the critical concentrations of magnetic atoms, p(c), at which the transition temperature goes to zero, are evaluated for several two- and three-dimensional lattice structures. The obtaine d values of T(c) and p(c) and the resulting phase diagrams for both bo nd and site cases are much more accurate than those estimated by the s tandard MFRG approach. Although preserving the same level of simplicit y as the MFRG, it is shown that the present EFRG method, even by consi dering its simplest size-cluster version, provides results that correc tly distinguishes those lattices that have the same coordination numbe r, but differ in dimensionality or geometry.