ZERO-FIELD MUON DEPOLARIZATION IN METALLIC-GLASS HYDRIDES

Measurements of the zero field muon spin rotation in two Ni-Zr glassy metal-hydrogen system are reported. In contrast with earlier muon work [1-4], good agreement with corresponding measurements made with nucle ar magnetic resonance is obtained. The muon depolarisation rate is fou nd to be due to the coupling of the muon spins and hydrogen nuclear mo ments. Muon motion is evident over the entire temperature range invest igated, 10 K to 340 K. Above about 200 K the correlation time of the d ipolar field at the muon has the same activation energy as the hydroge n jump rate obtained from the, nuclear magnetic relaxation. Below this temperature the interval between hops of the hydrogen atoms is appare ntly much longer than this correlation time.