Orientational dependence of exchange anisotropy of Mn-Ir/Co-Fe epitaxial bilayers

The exchange anisotropy of pseudo-single crystalline Mn-Ir/Co-Fe bilayers was investigated with different crystallographic orientations. The Cu buffer layer was deposited with applying the adequate substrate bias in order to achieve the epitaxial growth on MgO substrates. The structural analysis was performed by x-ray diffraction (XRD) and grazing incident x-ray diffraction (GID) with CuK α radiation source. The results show that the critical thickness of the antiferromagnetic layer d^cr_AF is similarly ∼3 nm, and that the unidirectional anisotropy constant J _k strongly depends on the crystallographic orientation.