OSCILLATING ANTIFERROMAGNETISM OF ULTRATHIN EUTE LAYERS

We study magnetic resonance on EuTe/PbTe superlattices. Analysis of th e magnetic dipole anisotropy in the superlattices and of the EPR ampli tude of isolated Eu ions in the PbTe wells shows that the diffusion at interfaces is very small. The real thickness of EuTe can be evaluated with an accuracy better than one monolayer. Since for EuTe layers thi cker than 2 monolayers there is no difference in the character of the antiferromagnetic resonance observed for even and odd numbers of monol ayers, we conclude that there is no static magnetization of the antife rromagnetic sublattices. Nevertheless, long range antiferromagnetic or der is clearly evident.