Abstract
We report on the effect of exchange interactions between antiferromagnetic (AF) NiCoO and ferromagnetic (FM) Permalloy (Py) layers in NiCoO/Py/MgO trilayers. The AF layer not only creates exchange bias in the FM layer but also enhances its coercivity substantially, by two orders of magnitude at low temperature. Unidirectional anisotropy was found to exist even in samples with just 10 Å of AF layer thickness. Studies on the dependence of coercivity and exchange bias on the angle between the applied field and the exchange bias direction were also performed and the results will be reported.
