Structure of Nickel Layers in Ni-C Multilayer Coatings: Influence of Annealing

Article type: Research Article

Authors: van Dorssen, G. E. | Puik, E. J. | van der Wiel, M. J. | Mackle, P. | Padmore, H. A. | Munro, I. H.

Affiliations: Association Euratom-FOM, FOM Institute for Plasma Physics Rijnhuizen, P.O. Box 1207, 3430 BE Nieuwegein, the Netherlands | Department of Chemistry, University of Manchester, United Kingdom | SERC Daresbury Laboratory, Warrington WA4 4AD, United Kingdom

Abstract: The structure of Ni-C multilayer and single nickel layer samples has been analyzed before and after annealing, using two techniques: fluorescence EXAFS (F1EXAFS) at the Ni-K. edge and CuKα reflection. Annealing at a temperature of 450°C resulted in a change in the structure of the nickel layers from amorphous like to crystalline like. A reduction of the Bragg reflectivity by a factor of 7 was also found. Comparison between the EXAFS data of the annealed sample and of a nickel foil show a difference in the amplitude of the EXAFS. This is ascribed to a non-Gaussian atomic distribution of the backscattering atoms in the annealed sample around their average positions, whereas the atomic distribution in the (polycrystalline) Ni foil is a Gaussian one. From the annealing experiments we conclude that no irreversible changes take place in the structure of the nickel layers at temperatures below 200°C.

DOI: 10.3233/XST-1992-3203

Journal: Journal of X-Ray Science and Technology, vol. 3, no. 2, pp. 109-117, 1992