ANISOTROPY STUDIES OF AFM COUPLED MBE GROWN CO CU(001) SUPERLATTICES/

We have studied the anisotropy behavior of antiferromagnetically (AFM) coupled fcc Co/Cu(001) sandwiches and superlattices. Magneto-optical Kerr effect measurements on samples with Cu film thicknesses in the ra nge of the second antiferromagnetic maximum reveal characteristic shap es of the hysteresis loops in close agreement with theoretical predict ions. For the AFM coupled samples we infer antiparallel spin orientati ons in remanence perpendicular to the originally applied magnetic fiel d direction. Changing the magnetic layer thickness and maintaining a c onstant thickness of the spacer completely alters the shape of the hys teresis loops. The loops of weakly coupled AFM layers show characteris tic steps, indicative for a rather unusual nonsymmetric spin state. Th is behavior can be explained by the competing effects of anisotropy wi th the exchange coupling.