CATION DIFFUSION IN MGABR4 (M = LI, CU, AND AG) STUDIED BY LI-7, CU-63, AND GA-71 NMR, BR-81 NQR, AND CONDUCTIVITY

Cation diffusion in MGaBr4 (M = Li, Cu) was confirmed by measuring the temperature dependence of the Li-7 and Cu-63 NMR linewidths. The acti vation energies for the cation diffusion were determined to be 36 and 44 kJ mol(-1) for LiGaBr4 and CuGaBr4, respectively. The activation en ergy for the reorientation of the GaBr4- anion in CuGaBr4 was evaluate d to be 62 kJ mol(-1) from (GaNMR)-Ga-71. The cation diffusion was als o confirmed for MGaBr4 (M = Cu, Ag) by observing a modulation effect o n the Br-81 NQR T-1. As expected from the modulation effect of NQR, th e ionic conductivity of AgGaBr4 was one order higher than that of CuGa Br4.