Emission channeling studies of Pr in GaN

We report on the lattice location of Pr in thin film, single-crystalline hexagonal GaN using the emission channeling technique. The angular distribution of $\beta^{-}$-particles emitted by the radioactive isotope $^{143}$Pr was monitored by a position-sensitive electron detector following 60 keV room temperature implantation of the precursor isotope $^{143}$Cs at a dose of 1 $\times 10^{13}$ cm$^{-2}$ and annealing up to 900°C. Our experiments provide direct evidence that Pr is thermally stable at substitutional Ga sites.