H. Metzner

Neutrino recoil experiments in metals

Using nuclear recoil due to neutrino emission during the electron-capture decay of111Sn to111 In in combination with111In/111Cd PAC we were able to obtain microscopic information about isolated low energy recoil processes in otherwise undamaged copper, silver, gold, aluminium, and lead.

Stage III Recovery in tantalum as compared with stage III in niobium

A recoil implantation technique using heavy ion nuclear reactions has been used to implant the PAC-activity111In deeply (several μm) into high-purity tantalum for a study of radiation induced lattice defects. In the region of annealing stage III (around 260K) trapping of defects is observed at the111In/111Cd probes in three well defined configurations. Striking similarities are found compared with the results of our former experiments on defect annealing in niobium.

PAC-STUDY OF DEFECTS IN n-TYPE GERMANIUM

Using perturbed angular correlations of γ rays the behaviour of Frenkel defects in n-type germanium is studied.111In/111Cd probes either serve as primary knock-on atoms in the production of Frenkel defects by neutrino recoil or as trapping agents for defects produced by electron irradiation. The neutrino recoil process leads to a defect which is characterized by vQ=e2qQ/h=42(2) MHz (η=0.6), while a defect with vQ=423(1) MHz (η=0) is observed after electron irradiation and thermal annealing.

Migration of vacancies in tantalum and stage III recovery in refractory bcc metals observed by PAC

Abstract Annealing of radiation-induced defects in high-purity tantalum was studied by perturbed angular correlation (PAC) between 77 and 380 K. Vacancy migration around 270 K is deduced. From comparison with PAC studies on niobium, molybdenum, and tungsten a highly systematic picture of stage III defects in 111 In traps in the refractory bcc metals evolves.

Development of solar cell material by PAC:111In probes in CuInS2 and related phases

Using metallic indium doped with radioactive111In as one of the starting materials samples of stoichiometric CuInS2, CuInS2 with excess of indium and sulphur, and stoichiometric CuIn5S8 were prepared. Perturbed angular correlations of γ rays emitted by111Cd are utilized to analyse the produced crystalline phases.