Mössbauer spectroscopy of interlayer boundaries in magneto-noncollinear [57Fe/Cr]12/MgO(100) superlattices

Abstract

Results are presented of Mossbauer analyses of [57Fe/Cr]12/MgO (100) superlattices. A combined approach was used, based on model calculations and a method of reconstructing the density distribution function P(Hhf) of the hyperfine fields. This procedure allowed us to systematically subtract the subspectra from the different neighborhood configurations of the resonant 57Fe atom. A detailed structural model was obtained for the Fe-Cr transition region from a “pure” Fe layer to a “pure” Cr layer. A deflection of the magnetic moment of the Fe atoms from the plane of the superlattice layers was identified in the interface of the Fe and Cr layers. The specific magnetic structure of the interface regions with different angular orientations of the magnetic moments of the Fe atoms relative to the plane of the layers (between 0 and 90°) is attributed to the coexistence of strong antiferromagnetic interaction between Fe and Cr atoms and an incommensurate spin density wave in the Cr layers.