THE EFFECT OF THE HYDROSTATIC-PRESSURE ON THE IONIC-CONDUCTIVITY IN APEROVSKITE LANTHANUM LITHIUM TITANATE

The ionic conductivity of the polycrystalline La-0.52+/-0.01 Li-0.35+/ -0.01 TiO2.96+/-0.02 has been measured as a function of hydrostatic pr essure up to 1.2 GPa in the temperature range between 238 and 294 K. T he conductivity decreased with an increase in pressure. The value of a ctivation volume for ionic motion derived from the data is positive an d almost invariable, between 1.6 +/- 0.2 and 1.7 +/- 0.2 cm(3)/mol, in the temperature range measured. This implies that a dilatation of the lattice occurs during the transport process. The activation energy of the ionic conductivity slightly increased with an increase in pressur e. The mechanism of the ionic conduction is discussed on the basis of these results.