Composition and lithium mobility have been analyzed in Li1+ x Ti (PO4)3 compounds (x = 0.2 and R3+ = Al3+, Ga3+, Sc3+, and In3+) by NMR and impedance spectroscopy. All of the compounds display the rhombohedral symmetry, and in all cases the trivalent cations are incorporated into the NASICON framework. From the analysis of the quadrupole constant (C Q) and spin−spin relaxation rate (T 2 -1) deduced from 7Li NMR spectra of Li1.2Ti1.8Al0.2(PO4)3, two regimes associated with local and long-range motions of lithium have been identified. From the analysis of the spin-lattice relaxation rate (T 1 -1) as a function of reciprocal temperature, the residence times of lithium at structural sites have been estimated and their dependence on temperature have been analyzed. Differences in activation energy deduced from NMR (0.22 eV) and conductivity (0.28 eV) measurements are discussed in terms of correlations in lithium motion that seem to decrease at increasing temperature.

No abstract

No abstract

No abstract

Compounds (M: Al, Ga, Sc, In) as Followed by NMR and Impedance Spectroscopy. -As revealed by XRD, NMR, and impedance spectroscopy most of the trivalent cations of the title compounds are incorporated into the NASICON structure, increasing the amount of mobile lithium ions. Analysis of the quadrupole constant and spin-spin relaxation rate deduced from 7 Li NMR spectra of the Al-containing compound indicate the existence of two regimes associated with local and long-range motion of Li. At increasing temperature, correlated motions decrease, reducing activation energy of lithium motion. -(ARBI, K.; LAZARRAGA, M. G.; BEN HASSEN CHEHIMI, D.; AYADI-TRABELSI, M.; ROJO, J. M.; SANZ*, J.; Chem.

No abstract

No abstract

No abstract