Santos, Jander P.; Sá Barreto, F.C. - In: Physica A: Statistical Mechanics and its Applications 421 (2015) C, pp. 316-329
Spin correlation identities for the Ashkin–Teller model are derived. From the correlation identities effective field approximation results for the magnetization, the specific heat, the critical frontiers and tricritical points are obtained. First-order transitions in three-dimensional lattices...