Microstructure of periodic metallic magnetic multilayer systems

The results of a complex microstructural analysis of periodic metallic magnetic multilayer systems (MLS) by Scanning/Transmission Electron Microscopy, Energy Dispersive X-ray microanalysis and Resonant X-ray Reflectivity (RXRR) are presented. The crystal structure of MLS based on Cr-Gd-Cr-Fe layers with different Cr layer thicknesses was revealed. The use of RXRR at the Cr and Fe absorption edges significantly improves the optical contrast between correspondent layers. A significant Cr diffusion was detected in adjacent layers. After that diffusion, Fe and Gd layers transform to the solid solution of Cr in Fe and in Gd respectively, without changing their crystal structure. Such Cr behavior may affect both the exchange coupling between Fe and Gd magnetic moments and the structural parameters of Gd layers, thus influencing drastically the magnetic moment. - Highlights: • The microstructure of Cr/Fe/Cr/Gd multilayer systems affects magnetic properties. • There is strong diffusion of Cr to the adjacent layers. • Top and bottom Cr/Gd interfaces have different morphology. • Gd layers adopted mostly fcc crystal structure. • Electron microscopy and X-ray resonant reflectivity results are self-consistent.