Study of thermal currents in powder beta-spodumene ceramics doped with CuO, FeO and TiO2

Abstract

Ternary - phase ceramic system of Li2O Al2O3 4 SiO2 doped with CuO, FeO and TiO2 has been prepared and subjected to d.c. electrical conductivity and thermally stimulated depolarization current (TSDC) measurements as a function of temperature (30-250 degreesC) and field strength. The electrical conductivity results are explained by assuming both ionic and electronic conduction mechanisms coexist with different contributions over the whole temperature range of experiments. TSDC spectra have been found to be characterized by a broad intense relaxation peak which can be attributed to an ionic charge polarization, The broad relaxation transitions are apparently a result of the nonuniform nature of this process. Activation energies are calculated for both d.c. electrical conductivity and TSDC according to Arrhenius equation and initial rise method respectively.