Structural and Dielectric Investigation of Lithium and Strontium Modified Bismuth Sodium Titanate Composite

Abstract

Crystal structure and Dielectric properties investigation of lead-free Bi_0.35Na_0.25Li_0.1Sr_0.3TiO₃ (BNLST) composite is reported. The required solid solution was synthesized using oxides and carbonates via the solid-state reaction method. The stoichiometrically weighed and mixed powder was calcined at 800 °C for 12 h, and the pellets were sintered at 1250 °C for 2 h. XRD measurements confirm the formation of single-phase rhombohedral perovskite structure and the crystal structure was refined using the X’Pert High-score plus software. The full-width half maxima of the XRD peak was used to compute the average crystallite size employing the Debye-Scherrer, Williamson-Hall, and Halder-Wagner techniques. The BNLST's dielectric measurements were performed as a function of temperature at five distinct frequencies in the range of 100 Hz–1 MHz. The phase transition temperatures are shifted toward room temperature with the doping of Li and Sr. The diffuseness parameters of the phase transition, the a.c. electrical conductivity and the activation energy are estimated for the BNLST composite.

Keywords:

• Bismuth sodium titanate (BNT)
• X-ray diffraction
• crystal structure
• dielectric
• electrical characterization

Acknowledgments

The authors acknowledge Prof. S. Srinadh and School of Physics, University of Hyderabad for providing the characterization facilities. Dr. Md Aahmad Mohiddon and Dr. Preeti acknowledge Honourable Vice-Chancellor of SRM University Delhi-NCR, Sonipat, Prof. P. Prakash and Dean of Academic Affairs, Prof. Samuel Raj for their kind support in establishing the Centre for Nanoscience and Nanotechnology.

Disclosure statement

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

Additional information

Funding

Dr. Anshu acknowledge DST (Ref. No.: SR/WOS-A/ET-38/2018) for providing the fund during this work.