Structural and Dielectric Properties of BaBi₂Nb₂O₉ Ferroelectric Ceramic Powders by a Solid State Reaction Method

Abstract

Ferroelectric BaBi₂Nb₂O₉ ceramic powders have been prepared using solid state reaction method. Samples have been sintered at four different temperatures of 800°C, 900°C, 1000°C and 1100°C each for 5 hrs. The XRD profiles have shown that the sample sintered at 1000°C (optimized) has displayed well defined features. Based on the profiles of XRD and Reitveild refinement analysis, samples are found in orthorhombic space group A21am (36). The thermal properties of the as synthesized sample have been investigated from the profiles of TG-DTA. Morphological analysis has been carried out from the SEM images and elemental analysis from the EDS profiles. For the temperature optimized sample, both Raman and FTIR spectral profiles have been studied. It is interesting to report that we could notice ferroelectric to paraelectric phase transition from the analysis of the dielectric properties as function of temperature (30–350°C) in the frequency range (1k Hz–1M Hz). Ferroelectric nature of the sample has been confirmed from the measurement of its hysteresis loop at the room temperature.

Keywords:

• Ferroelectric materials
• characterization