Structural study of Co/Gd multilayers by X-ray diffraction and GIXR

The objective of this work was the structural characterisation of Co/Gd multilayers grown by MBE process in various conditions. such as substrate composition, growth temperature, presence of buffer laver, bilayer thickness and thickness ratio of constituent sublayers. The structure of the sublayers and interfaces was studied by X-ray diffraction and grazing-incidence X-ray reflectivity (GIXR). The samples have been characterised by a conventional X-ray source as well as by synchrotron radiation, The obtained results show the enhanced diffusion of Co into Gd leading to thickness reduction of the pure Co sublayers. Simulations of the measured reflectivity suggest that a complex electron density profile occurs in the Co/Gd multilayers and the interfacial roughness of the Co/Gd interface differs from the roughness of the Gd/Co interface. (C) 2001 Elsevier Science B.V. All rights reserved.