Micro- and Nanostructure of Co/Pd and Co/Au Multilayers Studied with Transmission Electron Microscopy

Abstract

AbstractSeveral metallic multilayers with very thin magnetic Co layers display a preferred magnetization perpendicular to the interfaces. There are strong indications that the magnitude of this anisotropy depends critically on details of the microstructure of the multilayers, and especially on the atomic structure of the interfaces. The micro- and nanostructure of Co/Pd and Co/Au multilayers, which exhibit a large difference in lattice parameter (9% and 14% respectively), was studied by conventional transmission electron microscopy (TEM) and high resolution TEM (HREM). The multilayers, grown by vapor deposition, show a columnar structure and have a convex curvature in the growth direction. In Co/Au multilayers also the Au lattice is bent. Misfit dislocations are observed at the interfaces even for Co layers of one atomic layer thickness. Generally the interfaces show atomic roughness, which is more severe for Co/Au than for Co/Pd.