Structural Characterization of Multilayers Using X-ray Diffraction

ABSTRACTStructural deviations from ideal layering of bulk constituents can have dramatic effects on the properties of multilayered materials. We discuss three examples of the use of x-ray diffraction in non-standard geometries to examine these effects. In Mo/Ni multilayers, we use asymmetric diffraction and grazing incidence x-ray scattering (GIXS) to deduce the strain and intermixing. We find that coherency stresses between the BCC Mo and FCC Ni planes play a major role. In the Fe/Cr system, we use rocking curves and asymmetric scans about the small angle superlattice lines to investigate the nature and extent of layer roughness. We find that conformai roughness dominates our best samples, while non-conformal roughness increases with sputter deposition pressure. In the Gd/Co system, we use in-situ GIXS to investigate amorphization reaction during deposition. We find a strong diffusional asymmetry and rapid reaction during growth.