The phase transition of the spin-one Ising model with a random crystal field

Abstract

The effect of a random crystal field on the tri-critical behaviour of the spin-one Ising model is investigated by the use of the effective-field theory with correlations. The author finds that the order of the phase transition changes from first to second and that the temperature dependence of the magnetisation then exhibits some characteristic behaviour, when the crystal field fluctuates near the tri-critical point.