Influence of radiation-damage evolution on hyperfine interactions of implanted impurities:Tm169andLu175in Fe

The hyperfine interaction of ${}_{}{}^{169}{}_{}{}^{}\mathrm{Tm}$ and ${}_{}{}^{175}{}_{}{}^{}\mathrm{Lu}$ implanted in Fe and annealed, or implanted at high temperatures, was studied by time-integral and time-differential perturbed-angular-correlation experiments. The heat treatment was performed in order to modify the impurity-radiation-damage interaction in the sample. The annealing- and implantation-temperature dependences of the fraction of nuclei experiencing the hyperfine interaction are significantly different. The results are interpreted in terms of precipitation of an increasing proportion of implanted impurities. A discussion of their relation to the implanted-impurity lattice location is presented in a companion paper. A comparison of our results with other hyperfine-interaction results on rare earths implanted in iron suggests that after room-temperature implantation, all the implanted nuclei experience the same hyperfine interaction.