Magnetic properties of Fe/Nd artificial superstructure films

Multilayered films with artificial superstructures were prepared by alternately depositing Fe and Nd in ultrahigh vacuum. The magnetic properties are studied from⁵⁷Fe Mössbauer spectroscopy. The hyperfine field in Fe layers and the direction of Fe magnetic moments depend on the Fe and Nd layer thicknesses. For films with certain Fe and Nd layer thicknesses, the direction of Fe magnetic moments is in-plane at 300 K but changes to be perpendicular at low temperatures. The direction of Fe magnetic moments is discussed in relation with the magnetization of interface Nd atoms.