Crystallization Behavior and Microstructural Analysis of Strontium Rich () Glass Ceramics in Presence of

C R Gautam,Om Parkash,Devendra Kumar

doi:10.1155/2011/747346

Abstract

Crystallization and microstructural behavior of various strontium-rich glass ceramics in the system 65[(PbxSr1−x)TiO3]-24[2SiO2B2O3]-5[BaO]-5[K2O]-1[La2O3] () with addition of 1% La2O3have been investigated. The addition of La2O3has been found to play an important role in crystallization of perovskite (Pb,Sr)TiO3as a solid solution phase. Also, it causes a change in the surface morphology of the fined crystallites of the major phase. Differential thermal analysis (DTA) shows only one exothermic crystallization peak, which shifts towards higher temperature with increasing amount of strontium oxide. Glasses were subjected to various heat treatment schedules for the crystallization. Very good crystallization of strontium-rich glass compositions is observed. X-ray diffraction studies confirm that cubic perovskite lead strontium titanate crystallizes as major phase. Lattice parameter decreases with increasing strontium content similar to lead strontium titanate ceramics. Uniform and interconnected crystallites are dispersed in glassy matrix.

Highlights

Strontium titanate has a cubic structure above −163◦C where it transforms to a paraelectric phase
The present paper reports our results of investigations carried out to crystallize perovskite lead strontium titanate/perovskite strontium titanate solid solution phase in a borosilicate glassy matrix in presence of La2O3
Gold coatings were applied to the etched surface of various glass ceramic samples by the sputtering method in order to study the morphology of the different crystalline phases present by scanning electron microscopy (SEM)

Summary

Introduction

Strontium titanate has a cubic structure above −163◦C where it transforms to a paraelectric phase. The crystallization and microstructural behavior of glass ceramic with perovskite titanate phases, SrTiO3 [5,6,7,8,9,10,11,12,13,14] have been investigated. SrTiO3 could be crystallized as the major phase by addition of an appropriate concentration of K2O and selected heat treatment schedules. In these glass ceramics addition of La2O3 enhances the crystallization of strontium titanate phase and increases the dielectric constant enormously. The investigation on the phase development and microstructural characteristics of the glass ceramic in the system [SrOTiO2]-[2SiO2B2O3][K2O-BaO] showed that the solid solution of SrTiO3 with

Methods

Results

Discussion

Conclusion