Phase transitions in confined antiferromagnets

Confinement effects on the phase transitions in antiferromagnets are studie d as a function of the surface coupling v and the surface field h for b.c.c .(110) films. Unusual topologies for the phase diagram are attained for par ticular combinations of v and h. It is shown that some of the characteristi cs of the finite-temperature behavior of the system are driven by its low-t emperature properties and consequently can be explained in terms of a groun d-state analysis. Cluster variation free energies are used for the investig ation of the finite temperature behavior.