Formation of $^{117}In-H$ pairs after annealing of GaN implanted with $^{117}Cd(^{117}In)$

We report on the annealing behaviour of GaN grown on sapphire after implantation of 117Cd(117In). Isochronic annealing has been performed in order to remove the implantation induced lattice damage in evacuated quartz ampoules with additional Al. The extent of the lattice damage is investigated with perturbed gg-angular correlation spectroscopy (PAC). The implantation damage is annealed at temperatures above 1073 K to a large extent. 82(5) % of the probes are found on the Ga-site characterized by a quadrupole coupling constant of 20.9(1) MHz. After H loading, an additional interaction appears which is attributed to 117Cd(117In)-H pairs.