Spin-lattice relaxation rates and 1H nuclear magnetic resonance spectra were obtained from hydrogenated quasi-crystals, where x was equal to 0 or 2, and the H/metal atom ratio was 1.88. The nuclear magnetic resonance measurements were performed between 4 and 550K, using resonance frequencies of 8, 18, 55 and 200MHz. Theoretical 1H second-moment values were calculated on the basis of the Bergman-Mackay cluster models, and were compared with experimental values. The spin-lattice relaxation rate data revealed a distribution of activation energies for 1H diffusion through the quasi-lattice. The distribution was insensitive to the x-value. The low-temperature spin-lattice relaxation rate data revealed an additional low-temperature relaxation mechanism that was not entirely understood.

A.Shastri, E.H.Majzoub, F.Borsa, P.C.Gibbons, K.F.Kelton: Physical Review B, 1998, 57[9], 5148-53