THE EFFECT OF THE HYDROSTATIC-PRESSURE ON THE IONIC-CONDUCTIVITY IN A PEROVSKITE 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 pressure up to 1.2 GPa in the temperature range between 238 and 294 K. The conductivity decreased with an increase in pressure. The value of activation volume for ionic motion derived from the data is positive and 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 pressure. The mechanism of the ionic conduction is discussed on the basis of these results.