Magnetic Properties of Rare-Earth/Fe Multilayered Films with Artificial Superstructures
ABSTRACTBy using UHV deposition technique, multilayered films consisting of Fe and rare-earth (Dy, Nd or Y) layers were prepared. Magnetic properties of Fe layers were investigated from 57Fe Mössbauer spectroscopy. From SQUID magnetic measurements, the behavior of rare-earth layers was studied. In Fe/Dy and Fe/Nd multilayers, there often exists a large perpendicular anisotropy. Mössbauer spectra evidenced that, in certain samples, the magnetization changes the direction, from in-plane at high temperature to perpendicular at low temperature. The origin of the perpendicular anisotropy is attributed to interface rare-earth atoms which are magnetically coupled with ferromagnetic Fe layers even at higher than their bulk Curie temperatures.