Thermally stimulated currents of Lanthanum metaniobate ceramics

Abstract A series of LaNb 3 O 9 samples was prepared at 1325–1360 °C by the solid state reaction. The structures, temperature dependence of thermally stimulated currents and impedances were investigated. The samples show single phase of LaNb 3 O 9 by XRD analysis. The SEM analysis exhibits that the grain size increases and the porosity factor decreases with increasing sintering temperature. The stimulated current decreases with increasing sintering temperature and a large current of ∼ 110 µA without applied voltage was observed in the LaNb 3 O 9 sample sintered at 1325 °C. The polarization–electric field and temperature dependence of impedance results suggest that the temperature dependence of current does not originate from pyroelectric effect, but from the release of thermally stimulated current.