Ising antiferromagnets in a magnetic field

Abstract

The critical coupling strength and the thermal exponent of two-dimensional spin-1/2 and spin-1 Ising antiferromagnets in a magnetic field are investigated using phenomenological scaling. The results strongly support an analytic form of the critical curve, for s=1/2, postulated by Muller-Hartmann and Zittartz (1977). Phenomenological scaling is seen to give more reliable results than some conventional treatments.