SPIN-GLASS PHASE FOR THE DILUTED SITE-BOND-CORRELATED VERSION

We study the site-bond-correlated Ising model in the limit of the nega tive correlation parameter (alpha), within the mean-field renormalizat ion group scheme. The ferro-paramagnetic and spin-glass critical lines are obtained explicitly, for general coordination number Z. Phase dia grams are presented for Z = 6 and for some values of the parameter . I n this approach, two different exchange interactions (denoted models A and B) alpha are used. In the phase diagrams, for alpha not equal 1, a re-entrant phase is found in both models; when alpha = -1 this phase disappears.