Microstructures of a Pt/Ni/C multilayer system: an X-ray reflectivity and ion scattering study.

Microstructural characterization of a synthetic periodic and graded Pt/Ni/C multilayer system by X-ray reflectivity and ion scattering techniques is presented. The experimental reflectivity data are fitted with a theoretical multi-trilayer model with graded periodicity which increases from substrate to film surface along the surface normal direction. The increase in periodicity is found to be due to a linear increase in C-layer thickness from the bottom to the top, with a change of slope nearly at the middle of the multilayer stack. The thicknesses of Pt and Ni layers, the variation of C-layer thickness with depth, interface roughness of Pt/Ni, Ni/C, C/Pt interfaces are determined from the analysis of the reflectivity data. Rutherford backscattering spectrometry measurements were also made on the same sample. Simulated Rutherford back scattering spectrometry data using the parameters obtained from the analysis of the X-ray reflectivity data agree well with the measured Rutherford backscattering spectrum.