Phase Formation, Microstructure and Electric Properties of Vanadium Doped Lead-Free BaTi_0.91Sn_0.09O₃ Ceramics

Abstract

Lead-free Ba(Ti_0.91Sn_0.09)_1-xV_xO₃ (BTSV, x = 0, 0.005,0.010, 0.015, and 0.020) ceramics were prepared by the conventional solid-state sintering method with a calcination temperature of 1200 °C for 2 h and a sintering temperature between 1350 °C and 1400 °C for 4 h. The effect of vanadium (V) doping on the phase formation, microstructure and electrical properties of the ceramics was investigated. X-ray diffraction (XRD) measurements revealed that the ceramics with x = 0 and 0.005 had pure perovskite structures with no detectable impurity, while the ceramics with x ≥ 0.010 exhibited perovskite structures and had secondary impurity phases. Coexisting orthorhombic and tetragonal phases were observed and the Rietveld refinement analysis suggested that the tetragonal phase increased with increased V⁵⁺ substitution. When x increased from 0 to 0.010, the average grain size increased from 47 to 62 µm and then dropped, while the density (ρ) decreased from 5.98 to 5.64 g/cm³ when x increased. Furthermore, the BTSV ceramics exhibited increased porosity, Curie temperatures (T_C ∼ 42 °C to 52 °C) and coercive field (E_c), while the dielectric constant at the Curie temperature (ε_C) and the remnant polarization (P_r) of the ceramics decreased (∼18023 to 6110 and ∼7.42 to 4.88 µC/cm², respectively) when V⁵⁺ doping increased.

Keywords:

• Phase formation
• microstructure
• Rietveld refinement
• dielectric
• ferroelectric

Acknowledgments

The authors wish to thank the Department of Physics, Faculty of Science, Naresuan University for their supporting facilities. Thank are also given to Asst. Prof. Dr. Kyle V. Lopin for his help in editing the manuscript.

Disclosure Statement

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

Additional information

Funding

This work was financially supported by The National Science, Research and Innovation Fund (NSRF) through Naresuan University [R2566B038]. The work of N. Vittayakorn was funded by KMITL under Grant No. [KREF116501].