⁷Li NMR Spin‐Lattice Relaxation and Ionic Diffusion in Lithium Thioborate Glasses

Abstract

~~ and Ionic Diffusion in Lithium Thioborate Glasses 1313Conclusions It has been shown that deuteron NMR is well suited to obtain quantitative informations about the dynamics of the anisotropic reorientational as well as the site exchange motions of molecules specifically sorbed in the voids of zeolites. Intracrystalline diffusion constants can be obtained which compare very well with the data from proton pulsed field gradient measurements in single crystal zeolites (NaX). The 'H-NMR lineshape method applied presently allows to obtain intracrystalline diffusivities in zeolites in practical use, i.e. materials of sizes in the pm range (or even lower) and of rather high paramagnetic impurity levels.Financial support by the ,,Deutsche Forschungsgemeinschaft" and ,,Fonds der Chemischen Industrie" is gratefully acknowledged.'Li NMR spin-lattice relaxation rates at 16 MHz and 117 MHz have been measured at various temperatures for glasses in the non-oxide chalcogenide system B2S3-Li2S-LiX with X = C1, Br, I. As compared with the corresponding oxide glasses these materials are distinguished by a higher ionic conductivity, and the relaxation maxima are better accessible. The relaxation rates display anomalous temperature and frequency dependences. Attempts to interpret the non-BPP-type relaxation in terms of appropriate diffusion models are discussed.

Solid-state Li NMR with applications to the translational dynamics in ion conductors

“…At low temperature the ion motion is very slow and motional narrowing does not take place. Here the 7 Li NMR line-shape in glasses has been observed [346,353,354]. It consists of typically unstructured central and satellite contributions that can be described by two overlapping Gaussians.…”

“…The sulfide based glasses such as Li 2 S-B 2 S 3 [346][347][348] have also been an active area of study because of their fast ion conducting properties. Furthermore, they have similar properties to the oxide glasses [349,350].…”

Impedance spectroscopy and NMR studies of fast ion conducting chalcogenide glasses

“…In the fi"equency dependent region (ox » 1), the fit fails and de viates most for lowest temperatures and highest fi'equencies. The deviation at low tempera tures have previously been reported in lithium-based FIC glasses [87] and may be due to additional relaxation processes at low temperatures.…”

“…The comparison of the NMR and conductivity data has been considered by others [25,26,87,89], but not in the cases where the behavior could be tested over wide ranges of temperature and frequency as is done here, thus leading to a fortuitous agreement between the two P parameters. The difference found here for the values of P and the order of magnitude difference in the values of for conductivity and NSLR (Table 6.1) implies a different time dependence of the CP's.…”

NMR studies of structure and dynamics in glasses: Werner Müller-Warmuth's scientific contributions and impact

“…Indeed, several of the articles contained in this present issue report NMR studies of cation dynamics. New methods have emerged in the meantime, methods that are complementary (but in many ways also complimentary) to Mu¨ller-Warmuth's long-standing contributions to this research field [12,[16][17][18][19][20][21][22]30,34,43].…”