DEFECT TRAPPING OF ION-IMPLANTED DEUTERIUM IN FE

The trapping of ion-implanted deuterium (D) by lattice damage in Fe was investigated in the temperature range 90-500 K. The D depth profile was determined by measuring the proton yield from the 3He-excited nuclear reaction D(3He,p)4He, and the D lattice location was obtained by ion channeling. Linear ramping of the temperature produced a sharp detrapping stage at 260 K and a broader release extending over 350-450 K. The release-vs-temperature data were analyzed by solving the diffusion equation with appropriate trapping terms, yielding 0.48 and ?0.81 eV for the binding enthalpies associated with the two stages. The 0.48-eV trap corresponds to D at a near-octahedral interstitial site, where it is believed to be associated with a vacancy.