ION-IMPLANTED SURFACE ALLOYS IN NICKEL

Four surface alloys in nickel produced by high dose implantation of Ta** plus , Sn** plus , Er** plus and La** plus ions were investigated. Rutherford backscattering and channelling of 2. 9 MeV helium ion beam was employed to determine the substitutional solid solubilities and the bombardment-induced disorder. Ta, Sn and Er form substitutional solid solutions beyond solubility limits whereas La is found to be insoluble. It was shown that these and the other implanted alloys reported in nickel obey the recent ″modified Hume-Rothery rules″ proposed for metastable alloys formed by ion implantation. The radiation induced disorder extends well beyond the ranges of Sn** plus and Er** plus ions.