Perturbed angular-correlation experiments onIn111in oxidized fcc metals and their oxides

The perturbed angular correlation (PAC) method has been employed to study the hyperfine interaction of the 245-keV state in ${}_{}{}^{111}{}_{}{}^{}\mathrm{Cd}$, following ${}_{}{}^{111}{}_{}{}^{}\mathrm{In}$ implantation into the fcc metals Ag, Al, Cu, Ni, Pd, Au, and Pt and subsequent oxidation. Broad quadrupole frequency distributions around a peak frequency 〈${\omega }_1$〉=160 MHz were found in all systems and attributed to oxygen trapping at ${}_{}{}^{111}{}_{}{}^{}\mathrm{In}$. The fraction of oxidized ${}_{}{}^{111}{}_{}{}^{}\mathrm{In}$ increases with the oxidation temperature in such a way that about 50% of the implanted In ions have trapped oxygen at 60% of the melting temperature of the host. An interpretation of these frequency distributions has been attempted on the basis of PAC measurements for ${}_{}{}^{111}{}_{}{}^{}\mathrm{In}$ implanted into the metal oxides AgO, ${\mathrm{Ag}}_2$O, and ${\mathrm{In}}_2$ ${\mathrm{O}}_3$. In these systems, well-defined electric field gradients have been found which can be related to the respective crystallographic structures. In addition, the magnetic hyperfine interaction of ${}_{}{}^{111}{}_{}{}^{}\mathrm{In}$ in antiferromagnetic NiO proves substitutional implantation.