Defect formation and defect-impurity interaction in the hexagonal transition metals Re and Lu

Abstract

The formation of defects and their interaction with impurities in the hexagonal transition metals is largely unknown. We have employed the γ-γ perturbed angular correlation (PAC) technique to study the defects produced by the implantation of heavy ions into the transition metals rhenium and lutetium via the hyperfine interaction they produce at the lattice site of the PAC probe 111In. In rhenium, during an isochronous annealing program the formation of four different defect complexes at the implanted indium impurities was observed. It is concluded that the complexes are formed by the trapping of one or more vacancies at the In probe. In lutetium, for the first time, it was possible to introduce the In probe nuclei onto substitutional sites of the hexagonal Lu lattice. The corresponding quadrupole interaction frequency is v O = 8.52(3) MHz, η = 0. Further the formation of two different defect configurations at the In probe was observed. One is attributed to the trapping of an implantation induced single vacancy, whereas the second is due to the formation of In-H complexes with residual H dissolved in the sample. In both systems the temperature dependence of the interaction frequencies was measured.