Defect trapping of ionhyphen;implanted deuterium in copper

摘要

Trapping of ionhyphen;implanted deuterium (D) by lattice defects in copper has been studied by ionhyphen;beamhyphen;analysis techniques. The evolving depth distribution of D was monitored by using the nuclear reaction D (3He,p)4He, and the D lattice location was obtained by means of ion channeling. Linearhyphen;ramp annealing following a 15hyphen;keV D+implantation revealed two annealing stages at 250 and 300 K, respectively, corresponding to traphyphen;binding enthalpies of 0.22 and 0.42 eV, referenced to an untrapped solution site. From a comparison of these results with theoretical calculations based on the effectivehyphen;medium theory, the 0.42hyphen;eV trap has been associated with monovacancies and perhaps small vacancy clusters, an assignment supported by previous positronhyphen;annihilation experiments, whereas the 0.22hyphen;eV trap tentatively is associated with selfhyphen;interstitials. The channeling data have been analyzed, utilizing an extended multirow continuum model, and it is found that the data for D trapped to vacancies cannot be interpreted in terms of a single lattice site. This is consistent with the theoretical effectivehyphen;medium results, which show that D trapped at a vacancy is delocalized with maximum probability between the vacancy and the octahedral interstitial site, consistent with the experimental findings.