Polarized neutron diffraction studies of Gd-Y synthetic superlattices

The microscopic magnetic structures of coherent, single-crystal epitaxially grown superlattices consisting of successive bilayers of NGd basal planes of hexagonal-close-packed Gd followed by NY such atomic planes of nonmagnetic Y have been studied by polarized neutron diffraction. It has been found that for NGd=10, either a simple parallel alignment of the ferromagnetic Gd layers or an antiphase domain structure occurs, depending on the number of intervening Y planes in an oscillatory manner. These data are consistent with a RKKY coupling mechanism between Gd layers. In addition to the investigation of the interlayer interactions, measurements of the magnetization profile across the thickness of a Gd layer have been performed.