Temperature Dependence of Dielectric Conductivity in KTaxNb1-xO3 System for x ≤ 0.5

Abstract

Pellet samples of mixed potassium tantalate niobate (KTa_xNb_1-xO₃), for compositions x = 0, 0.1, 0.2, 0.3, 0.4 and 0.5 were prepared by solid-state reaction method. The calcined mixture was pressed at 0.2 GPa and sintered in a closed furnace to form 8 mm diameter pellets. Temperature variation of dielectric conductivity of the prepared samples has been studied in the frequency range from 0.1 KHz to 1 MHz. Dielectric conductivity has been observed increasing with increasing frequency and with increasing x values, for x £ 0.4; for x = 0.5, conductivity decreases at 0.1, 1 and 10 KHz. At 100 and 1000 KHz conductivity decreases for x = 0.3, showing the MPT region. Anomalies have been observed near the transition temperatures of the samples in temperature-dielectric conductivity curves.