Within the density functional theory the electronic structure of triple molybdates Li2M3Al(MoO4)4, where M = Cs, Rb, is studied for the first time. It is found that all molybdates studied belong to wide band insulators with a band gap of ~4 eV. Quadrupole frequencies and asymmetry parameters of the electric field gradient near magnetic 7Li, 27Al, 87Rb, and 133Cs nuclei are calculated and experimental NMR spectra are interpreted.

Изучены спектры ЯМР (MAS) 6Li, 7Li сложных молибдатов состава Li2Zn2(MoO4)3 и LiRb3Hf2(MoO4)6 с лионситоподобной структурой в интервале температур от 25 до 100°С. Дано отнесение линий ЯМР. Показано, что присутствие в структуре лионсита переходного металла Hf со степенью окисления +4 способствует увеличению подвижности ионов лития по каналам кристаллической структуры.

6Li and 7Li MAS NMR spectra of complex Li2Zn2(MoO4)3 and LiRb3Hf2(MoO4)6 molybdates of lyonsite-type structure are studied at temperatures ranging from 25 to 100°C. NMR signals are attributed to their sources. It is shown that the presence of a transition metal such as Hf in the +4 oxidation state in the structure of lyonsite contributes to the increased mobility of lithium ions along the channels of the crystal structure.

Nuclear magnetic resonance (magic angle spinning) spectra of 7 Li, 27 Al, 87 Rb, and 133 Cs nuclei are measured in Li 2 M 3 Al(MoO 4 ) 4 triple molybdates ( M = Rb, Cs) for the first time. Analysis of the nuclear magnetic resonance spectra reveal considerable asymmetry in the distribution of the electric charge throughout the crystal lattices of the compounds.

The glassy LiPO3/crystalline SiO2 (0–20 vol%) composite solid electrolytes have been obtained by glass softening. The XRD data confirmed that the amorphous state of LiPO3 was retained in the composite. The transport characteristics were measured by impedance spectroscopy and NMR technique with 6Li and 7Li isotopes. The concentration dependences of specific conductivity have a maximum at ~5 vol% of SiO2. According to the conductivity data fitting with a mixture equation, the conductivity of LiPO3/SiO2 layer is 8.6 (at 50 °C) to 17 (at 200 °C) times higher compared with the starting LiPO3 glass. The NMR data confirm that the number of mobile Li ions in the composite increases. In case of porousless composites, the conductivity maximum was at ~15 vol% of SiO2. Thus, a slight composite effect was found in the examined glassy LiPO3/crystalline SiO2 system.