Study of universality class for site-bond correlated diluted spin systems in the n-vector model

Abstract

Using the mean-field renormalization group approximation, the n-vector model is used to study the critical properties of the site-bond correlated diluted model on d-dimensional hypercubic lattices, by employing two different exchange interactions. The critical temperature and percolation concentrations are obtained. The phase diagram in the T– p plane on a simple cubic lattice for the classical Heisenberg ( n=3) model is presented. The values for the critical magnetic and thermal exponents for classical XY and the Heisenberg models, respectively, are obtained and the results, when compared with the other methods, are an improvement, even for small size clusters. In addition, the relation between the initial slopes for correlated and uncorrelated models is universal.