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Fast field cycling (1)H NMR relaxometry is applied to determine the dispersion of spin-lattice relaxation time T(1)(omega) of the glass former glycerol in broad temperature (75-360 K) and frequency (10 kHz-30 MHz) ranges. The relaxation data are analyzed in terms of a susceptibility chi(")(omega) proportional, variantomegaT(1)(omega), related to the second rank (l=2) molecular orientational correlation function. Broadband dielectric spectroscopic results suggest the validity of frequency temperature superposition above the glass transition temperature T(g). This allows to combine NMR data of different temperatures into a single master curve chi(")(omegatau(alpha)) that extends over 15 decades in reduced frequency omegatau(alpha), where tau(alpha) is the structural alpha-relaxation time. This master curve is compared with the corresponding ones from dielectric spectroscopy (l=1) and depolarized light scattering (l=2). At omegatau(alpha)<1, NMR susceptibility is significantly different from both the dielectric and light scattering results. At omegatau(alpha)>1, there rather appears a difference between the susceptibilities of rank l=1 and l=2. Specifically, at omegatau(alpha)>>1, where the susceptibility is dominated by the so-called excess wing, the NMR and light scattering spectra (both l=2) rather coincide with each other and are about three times more intense than the dielectric (l=1) spectrum. This is explained by assuming that the high frequency dynamics correspond to only small-angle excursions. Below T(g), dielectric and NMR susceptibility compare well and exhibit an exponential temperature dependence.

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By nuclear magnetic resonance spin-lattice relaxation dispersion in LaF3, measured in the frequency range from 60 kHz to 284 MHz, dynamic processes with correlation times in the range from 10-5 to 10-10 s are studied. This allows us to trace fluorine dynamics in the temperature range from 303 to 1400 K. Two motional modes, a fast one and a slow one, are identified. Both motional processes are found not to be of Bloembergen-Purcell-Pound type but obey a log-Gaussian distribution of correlation times, thus reflecting the potential energy landscape in the superionic state. Below 1000 K, the activation energy of fluorine diffusion is 0.36 eV for the fast ions, and 0.57 eV for the slow ones. At higher temperatures, the activation energies change drastically. Above 20 MHz, where most relaxation studies have been performed so far, an additional contribution to relaxation, which is probably induced by paramagnetic centres, is found to be dominant.

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