Exchange anisotropy of (001)-oriented Mn80Ir20/NiFe epitaxial bilayers

Abstract Exchange anisotropy was investigated for Mn 80 Ir 20 /NiFe epitaxial bilayers with (0 0 1)-orientation grown applying a magnetic field along either the [1 0 0] or the [1 1 0] direction and was compared with that for Mn 89 Pt 11 /NiFe bilayers. The Mn 80 Ir 20 /NiFe bilayers exhibited a large exchange bias field without post-annealing. Its easy direction of the unidirectional anisotropy was always parallel to the 〈110〉 direction. This result was similar to that of Mn 89 Pt 11 /NiFe bilayers. On the other hand, MnIr/NiFe bilayers showed magnetic anisotropy torque curves significantly different from Mn 89 Pt 11 /NiFe bilayers. Mn 89 Pt 11 /NiFe showed a very large 4-fold component while Mn 80 Ir 20 /NiFe showed a much smaller one.