IONIC-CONDUCTIVITY OF CERAMICS PREPARED BY SINTERING OF M2O-LN2O3-2SIO2 MIXTURES (M = LI, NA, K, RB, CS LN = LA, ND, SM, GD, DY, Y, HO, ER, YB)

Ionic conductivities have been measured over a wide range of temperature and frequency for ceramics prepared from M2O-Ln2O3-2SiO2 mixtures. In the samarium series, the activation energy and conductivity at 500-degrees-C were estimated to be 78.4 kJ mol-1 and 4.9 x 10(-4) S cm-1 for Li, 69kJ mol-1 and 1.1 X 10(-4) S cm-1 for Na, 18 kJ mol-1 and 1.2 x 10(-2) S cm-1 for K, 33 kJ mol-1 and 3.99 x 10(-3) S cm-1 for Rb, and 66 kJ mol-1 and 3.8 X 10(-6) S cm-1 for Cs. The values of the a and c parametefs in the hexagonal phase of K2O- and Rb2O-Ln2O3-2SiO2 are greater than the interpolated values for the Li and Cs series of hexagonal phase. The highest conductivity is achieved for K2O-Nd2O3-2SiO2 in a series of M2O-Ln2O3-2SiO2.