Phase diagram of thin antiferromagnetic films in strong magnetic fields

A theoretical study of the phase diagram of antiferromagnetic thin films is presented. The theory is based on a numerical self-consistent local-field calculation that allows for size and surface effects. The properties of magnetic structures as functions of the temperature and external field are calculated. Spatially nonuniform canted states are shown to intermediate the transition from the antiferromagnetic to the spin-flop phases. The model is applied to thin films of ${\mathrm{FeF}}_2$ and ${\mathrm{MnF}}_2$ as examples in order to clarify the role of anisotropy.