Universality and crossover in an Ising-like model

Abstract

The critical behaviour of an anisotropic n-vector model with purely Ising-like coupling is studied on the FCC lattice by means of high-temperature series. The model includes the s=1/2(n=1) and s= infinity (n=3) Ising models as special cases and exhibits rigorously mean-field behaviour at n= infinity . The crossover region 1/n to 0, t identical to (1-v/vc) to 0, is examined in detail. The susceptibility exponent gamma remains Ising-like for all finite n. The critical temperature and critical susceptibility amplitude vary as 1/n.