Muon spin rotation experiments were performed on monocrystalline samples of ScHx, where x was equal to 0, 0.05, 0.10 or 0.25, in order to investigate the muon location, and variations in muon dynamics. The angular and magnetic field dependences of the muon spin rotation relaxation rates showed that, at temperatures below 50K, the muon was localized at interstitial tetrahedral sites. The results for pure Sc were consistent with the assumption that the muon underwent rapid tunnelling between 2 adjacent T sites, separated by 0.18c, above and below the a-b plane. This value for the muon position along the c-axis was very near to that of 0.194c which had been found (for D in Sc) by using neutron diffraction techniques. The anisotropy of the relaxation rate in low magnetic fields depended sensitively upon the H concentration. This indicated a change in the ratio of the radial, muon-induced and partly inherent, uniaxial electric field gradients at the position of the Sc nuclei.

F.N.Gygax, A.Amato, R.Feyerherm, A.Schenck, I.S.Anderson, T.J.Udovic, G.Solt: Journal of Alloys and Compounds, 1995, 231, 248-51