CUBIC MODELS WITH RANDOM ANISOTROPY

A Monte Carlo algorithm has been used to study the cubic ferromagnet with a random uniaxial single-site anisotropy on simple cubic lattices, in the strong anisotropy limit. For both two-component and three-component spins the phase diagram contains a ''domain-type'' ferromagnetic phase for strong random anisotropy, in addition to the simple ferromagnetic phase which is seen for weak random anisotropy. For two-component spins both paramagnet-ferromagnet transitions seem to be second order. For three-component spins the magnetization probably disappears discontinuously, and there appears to be a thin layer of infinite susceptibility phase between the paramagnetic and ferromagnetic phases.