Deuteron spin diffusion and spin lattice relaxation in amorphous solids

The effect of spin diffusion on the decay of longitudinal magnetization in deuterated glassy systems is investigated. The decay of longitudinal magnetization was measured for different dilutions of amorphous deuterated toluene in protonated toluene. For increasing dilution the magnetization was found to decay more slowly, indicating the importance of spin diffusion also in deuteron spin systems. A strong correlation between the apparent width of the distribution of spin lattice relaxation times and the absolute value of the average spin lattice relaxation time was found. This correlation can be explained in terms of spin diffusion. A simple model is able to reproduce the main features of the observed phenomena. The initial decay rates are shown to be independent of spin diffusion. Conclusions concerning the frequency dependencies of observed average spin lattice relaxation times and width parameters are drawn. (C) 1995 American Institute of Physics.