Ion conduction in one-dimensional ionic conductor A(x)Ga(8)Ca(8+x)Ti(16-x)O(56) (A = K, Rb, Cs)

Conduction of ions blocking the motion of mobile alkali ions in single crys tal of one-dimensional (1D) superionic conductor alkali gallotitano-gallate A(x)Ga(8)Ga(8+x)Ti(16-x)O(56) (A = K, Rb, Ca) was studied by an AC complex electrical conductivity measurement from 20 Hz to 98 GHz. Data were analyz ed by the moving box model. The complex conductivity of blocks showed the p ower law for frequency. The conduction process was thermally activated and values of the activation energies were large, 1.22, 1.20, and 1.05 eV for K GGTO, RGGTO, and CGGTO, respectively. The conduction mechanism was discusse d by the motion of the extra oxygen ions in the conduction path (1-D tunnel ) and the push-pull motion of the Ga3+ ions between the tetrahedral site in the tunnel framework and interstitial sites in the conduction path. (C) 19 99 Elsevier Science B.V. All rights reserved.