Multifunctional transparent glass nano/ microcomposites

Abstract

Borate-based glass nano/microcomposites comprising members of the Aurivillius family of ferroelectric oxides (Bi VO . , SrBi Nb O ) along with LiNbO have been successfully fabricated.

The crystallite size of the active phase was varied either by changing the composition or by altering the heat-treatment temperature. Structural, microstructural, dielectric, pyroelectric, ferroelectric, linear, and non-linear optical properties were systematically studied, providing insight into the processing-structure-property correlations in these glass nano/microcomposites.

The formation of the layered perovskite SrBi Nb O phase in the Li B O glass matrix was invariably found to proceed via an intermediate fluorite phase. A plausible mechanism for fluorite phase formation prior to perovskite crystallization was briefly discussed.

Based on crystallization kinetics, studied using the Johnson-Mehl-Avrami (JMA) equation under both isothermal and non-isothermal conditions with differential thermal analysis, a two-stage heating technique was employed. This approach improved the transmission characteristics of LiNbO crystallites in the Li B O glass matrix.

Solid solutions in the ferroelectric systems Sr Ba Nb . Ta . O were also investigated. The tunability of the Curie temperature and the Ta-induced disorder were established.