ENHANCEMENT OF DIELECTRIC PROPERTIES BY OPTIMIZATION OF SINTERING CONDITION IN TUNGESTEN- BRONZE STRUCTURED Ba5SmTi3Nb7O30 FERROELECTRICCERAMICS

Abstract

Abstract In this work, polycrystalline Ba5SmTi3Nb7O30 tungsten–bronze structured ferroelectric ceramics were synthesized by solid-state reaction technique at different sintering temperatures and durations. The X-ray diffracto- grams reveal the formation of the compounds in ortho- rhombic crystal system. The density of the compound is observed to increase with increase in sintering temperature and duration. Scanning electron microscopy (SEM) has been used for the microstructural investigation. Detailed dielectric properties of the compounds have been studied as a function of frequency and temperature. The variations of dielectric constant "0 r � with temperature show that the compounds undergo a diffuse type ferro-paraelectric phase transition. The dielectric constant is found to increase with the increasing sintering temperature and duration. In all the samples, the variation of dielectric loss (tan δ)with temperature i...