Ion Mobility and Conduction in the (NH 4 ) 6 LiHf 2 Zr 2 F 23 Compound

The ion mobility and conduction in the (NH4)6LiHf2Zr2F23 compound are studied by 1H, 19F NMR and impedance spectroscopy methods. The types of ion motion in fluoride and ammonium sublattices are determined in the temperature interval from 150 to 450 K. As a result of the order‑disorder phase transition at the temperature above 400 K, the metastable high-temperature β-modification of this compound with ionic diffusion in both sublattices is formed. The conductivity in this compound at 450 K is found to be 4.5 × 10–3 S/cm.