Synthesis and characterization of nanocrystalline SrBi2Nb2O9 ferroelectric ceramics using TEA as the polymeric matrix

The processing conditions, reaction mechanism, fine structure of the powders, microstructure, and dielectric properties of SrBiNb2O9 (SBN) were systematically studied. A relative density of >80% was obtained using a two-step sintering process at moderate pressure. XRD showed that a single phase with the layered perovskite structure of SrBi2Nb2O9 (SBN) was formed after calcining at 600 °C. No intermediate phase was found during heat treatment at and above 600 °C. The crystallite size (D) and the effective strain (η) were found to be 38.8 nm and 0.01475, respectively, while the particle size obtained from TEM was laid between 25 and 36 nm. SEM revealed that the average grain size after sintering at 900 °C for 4 h was 0.67 μm. Dielectric constant and corresponding tangent loss were measured in the frequency range from 1 kHz to 1 MHz from which the Curie temperature (Tc) was found to be at 450 °C.