Search

The lattice location of $^{147}$Nd and $^{147^{*}}$Pm in thin-film, single-crystalline hexagonal GaN was studied by means of the emission channeling technique. The angular emission yields of $\beta^{-}$-particles and conversion electrons emitted by the radioactive isotopes $^{147}$Nd and $^{147^{*}}$Pm were measured using a position-sensitive detector following 60 keV room temperature implantation at a dose of 1 $\times 10^{13}$ cm$^{-2}$ and annealing at 900°C. The emission patterns around the [0001], [1102], [1101], and [2113] crystal axes give direct evidence that the majority (70%) of Nd and Pm atoms occupy substitutional Ga sites.

On-line Perturbed Angular Correlation (PAC) experiments were performed on the 66.0 keV excited state of 127 Cs, using the γ (114.7 keV)–e − L (66.0 keV) cascade from the decay of the short-lived 127 Ba ( T 1/2 =13 min) isotope produced at the ISOLDE facility at CERN. The PAC experiments were performed with an optimized γ–e − spectrometer coupled to the ISOLDE beam line, which allowed simultaneous implantation and measurement. The optimization of the experiment is described and the first results on metallic foils and single crystals of Al, Be, Ga, Zn, and Ni are presented and discussed. The derived nuclear moments of the 66.0 keV excited state of 127 Cs are | μ |=2.9(2) μ N and | Q |=0.58(12) b . Applications of this new PAC isotope are outlined.