Structural Evolution, Dielectric, Ferroelectric and Thermal Properties of Pristine and (Sr, Mn) Co-doped BaTiO₃

Abstract

Nanocrystalline specimen of pure BaTiO₃ (BTO) and Ba_0.9Sr_0.1Ti_0.95Mn_0.05O₃ (BSTMO5) has been synthesized through solid state route. XRD patterns reveal uni-phase tetragonal configuration with P4mm space group. The crystallite size and strain have been evaluated by fitting the data with Williamson-Hall equation. Raman spectra are consistent with the tetragonal phase of BTO. Colossal value of dielectric constant is observed for BTO samples. The temperature-dependent P-E loops reveal highest value of polarization at 323K. Differential thermal analysis (DTA) is used to evaluate the specific heat (C_p) of the samples. Doping with (Sr, Mn) raises the Curie temperature hence enhancing the temperature stability of BTO. It can broaden the temperature range over which the material exhibits desirable ferroelectric and dielectric properties. This improved stability along with high dielectric permittivity is advantageous for applications that require operation over a wide temperature range. The band gap enhanced for BSTMO5 making it suitable for usage in optoelectronic devices.

Keywords:

• Lead-free ceramic
• dielectric
• ferroelectric
• Raman spectroscopy
• differential thermal analysis
• band gap

Acknowledgments

Authors are grateful to the University Sophisticated Instrument Facility (USIF), Aligarh Muslim University, Aligarh for SEM and Raman measurements. Dr. M. Jane Alam, Spectroscopy lab, Physics Department, AMU, Aligarh, is thanked for conducting the optical characterizations.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by DST, Government of India, under the INSPIRE Fellowship Program (DST/INSPIRE Fellowship/2017/IF170728).