Electrical conductivity of Li2TiO3 ceramics

The microstructure of Li2TiO3 ceramics, proposed as blanket material in deuterium-tritium fusion reactors, plays an important role for this application; grain size and grain shape determine to a considerable degree the properties in question. Electrical properties may reflect certain characteristics of the microstructure to some extent. In this communication impedance spectroscopy is applied to analyse electrical charge transport in ceramics of monoclinic beta-Li2TiO3, synthesized in different conditions. Li+ ions are suggested to be the majority charge carriers. Typical activation energies for charge transport, deduced from the DC conductivity sigmaDC, are EA0.6-0.9eV and the bulk sigmaDC (573K)3X10-6Omega-1cm-1. The DC and AC conductivities show some features of the microstructure. Anomalies in the DC conductivity at 570K-900K are indicative of a change in conduction which is tentatively assigned primarily to the formation of nuclei of the cubic gamma-Li2TiO3 phase in this temperature region, well below the first order phase transition beta- > gamma at 1425K-1485K.