Structural, dielectric and ferroelectric properties of SBN ceramics synthesized by microwave reactive sintering technique

Abstract

Strontium barium niobate (SrxBa1−xNb2O6 with x=0.53/SBN53) ceramics have been synthesized by microwave reactive sintering technique. Powders corresponding to SBN53 stoichiometric composition were calcined at 1200°C for 20, 30 and 45min; and the green pellets made of calcined powders were sintered at 1300°C for 20, 30 and 40min in a microwave furnace. Ceramics with tungsten bronze type crystal structure were obtained in relatively much less processing time as compared to conventional processing. The reaction between strontium niobate (SN) and barium niobate (BN) phases present in the calcined powders enhances the densification process of the ceramics during sintering. A relative density ∼98.3% was obtained in SBN53 ceramics sintered for 40min. Curie transition temperature (Tc) and dielectric constant (ɛr) were found to vary from 113 to 135°C and from 1350 to 2500, respectively, depending on the processing conditions.