Composition Dependences of the Thermal and the Electrical Properties in Lithium-Potassium-Niobium-Silicate Glasses

摘要

We have investigated the composition dependences of the thermal and the electrical properties in lithium-potassium-niobium-silicate (2(Li i _xKx )Nb03-Si0 2 ) glasses. Glass samples were prepared by using a twin roller quenching method. Differential thermal analysis was used to measure the thermal characteristics, and electrical measurements were carried out in the frequency range from 102 Hz to 1.5 x 10~7 Hz. The frequency dependence of thelectrical data was analyzed in the frameworks of the electrical modulus and the complex impedance formula. We found, from the thermal analysis, that the characteristic temperature' for- the crystallization of the glass varied nonlinearly with the composition. The composition dependence of the dc resistivity and the activation energies of the dc and the ac electrical conductivities obtained both from the impedance Cole-Cole formula and the modulus analysis also showed nonlinear behaviors. The composition-dependent scaling plots for the imaginary part of the electrical modulus at a selected temperature overlapped on a single master curve, irrespective of the composition.