Phase States and Dielectric Properties of Li0.17Na0.83NbуТа1 –уO3 Ceramic Solid Solutions Prepared by High-Pressure, High-Temperature Synthesis

Abstract

The electrical properties and phase states of Li_0.17Na_0.83Nb_уТа_{1 –у}O₃ (y = 0.1–0.5) ferroelectric perovskite solid solutions prepared by high-pressure, high-temperature synthesis have been studied using impedance spectroscopy. The ε'(T) and σ_sv(T) curves of the solid solutions have been shown to have anomalies due to phase transitions of the materials. Their Curie temperature has been found to decrease with increasing Ta concentration. The static electrical conductivity of the solid solutions has been measured as a function of temperature and the enthalpies of activation of charge carriers in them have been evaluated. The Li_0.17Na_0.83Nb_0.1Та_0.9O₃ solid solution has been shown to be a high-temperature superionic conductor. Possible mechanisms of the observed phenomena are discussed.