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

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 degrees C for 20, 30 and 45 min; and the green pellets made of calcined powders were sintered at 1300 degrees C for 20, 30 and 40 min 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 similar to 98.3% was obtained in SBN53 ceramics sintered for 40 min. Curie transition temperature (T-c) and dielectric constant (epsilon(r)) were found to vary from 113 to 135 degrees C and from 1350 to 2500, respectively, depending on the processing conditions. (C) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.