Electrical and Pyroelectric Measurements on Charge Imbalanced Sr₂Bi₂Nb₃O₁₂ Sol-Gel Ceramic

Abstract

Oxygen-deficient and charge- imbalanced polycrystalline materials of three-layered Auruvillius compound, namely Sr₂Bi₂Nb₃O₁₂ (SBN), was synthesized by Sol-Gel method. X-ray diffraction analysis was made on SBN and lattice parameters were calculated. Electrical impedance and Pyroelectric measurements were performed on SBN. The broad peak observed in the dielectric permitivity data indicates that the transition is diffused phase transition (DPT) and the modified Curie-Weiss law was used to describe the DPT of SBN. The sharp intensity peak observed at 176 and 219 cm⁻¹ in Raman spectra is an indicative of Sr-O-Sr and Sr-O-Bi bonds and its competitive interactions. The peaks of FTIR spectra appeared at 610 cm⁻¹ confirmed the same. The nature of difffused type was attributed to compositional heterogenity and the results were corroborated with the log-log spectroscopic plots of impedance,modulus and permitivity for better understanding of the disorder ferroelectric behavior of the sample. The broad semicircle behavior observed in the complex impedance aswell as modulus plot, associated with grain and grain boundary, confirm the same.

Keywords:

• Component
• BLSF
• pyroelectric
• impedance
• Raman and FTIR spectra

Acknowledgment

The authors thank the Department of Science and Technology, New Delhi for providing the financial assistance through the sponsored project No. SR/S2/CMP-25/2010.