CUXY COMPOUNDS AS THIN-FILMS - CRYSTALLOGRAPHIC AND COMPOSITIONAL ANALYSES OF COPPER RICH PHASES

This study which relates the interdiffusions of Y films deposited onto Cu substrate, is devoted to the Cu-rich phases formed at temperatures higher than 553 K. The same experimental procedures (concentration pr ofiles, X-ray and electron diffraction patterns) as those mentioned in a preceding investigation, were used to characterize the compounds fo rmed throughout the thin layers. In samples deposited by flash evapora tion the Cu9Y2, beta-Cu5Y and Cu7Y compounds were detected in the cour se of successive annealings up to 1053 K. Moreover, electron diffracti on patterns reveal that some particles scattered all over the sample a re characterized by superlattice structures. From this study the forma tion of Cu4Y for heavy rare earth elements has been excluded. In sputt ered films the formation of yttrium hydrides or oxides (YH2, Y2O3) str ongly perturbs the Cu diffusion process. (C) 1998 Elsevier Science S.A .