Temperature and fluence effects in lead-implanted cobalt single crystals

Abstract

The channelled sputtering yields of the h.c.p. and f.c.c. phases of cobalt depend on the crystal structure and the radiation-induced damage. Earlier irradiations of cobalt with argon ions channelled in the 〈0001〉 hcp direction give sputtering yields higher than expected in the temperature range 100–350°C. This effect was attributed to a combination of radiation-induced damage and a possible implantation-induced h. c. p. → f. c. c. phase transition. Sputtering yields for cobalt single crystals irradiated with 150 keV Pb + ions along the 〈0001〉 direction of the h.c.p. phase and the 〈111〉 direction of the f.c.c. phase have been measured using the weight loss method. The radiation damage and the amount of lead retained in the implanted surface have been investigated by “in situ” Rutherford backscattering-channelling analysis. Measured partial sputtering yields of lead of approximately 1 atom ion −1 indicate preferential sputtering of lead atoms.