Enhanced Dielectric, Piezoelectric, and Mechanical Performances of Barium Strontium Titanate-Modified (Bi_0.487Na_0.487La_0.017)TiO₃ Lead-Free Ceramics

Abstract

The (1−x)(Bi_0.487Na_0.487La_0.017)TiO₃-x(Ba_0.7Sr_0.3)TiO₃ or BNLT-BST were fabricated by a solid-state mixed oxide. With increasing BST content, a phase transition from the BNLT rhombohedral to the BST tetragonal was observed. The addition of BST inhibited grain growth which resulted in the improvement of the densification, mechanical and dielectric properties. The maximum of HV (6.68 GPa), HK (6.61 GPa), E (89 GPa), K_IC (1.55 MPa m^1/2), ε_r (1911) and tan δ (0.0394) were observed for the x = 0.20 ceramic. The highest d₃₃ (140 pC/N) and g₃₃ (12.69 × 10⁻³Vm/N) were observed for the x = 0.05 ceramic. The J decreased while ρ increased with an increasing amount of the additive.

Keywords:

• Lead-free piezoelectric
• mechanical
• dielectric
• piezoelectric voltage constant
• leakage current density

Acknowledgments

This work was supported by Department of Physics and Materials Science, Faculty of Science, Science and Technology Research Institute, Chiang Mai University. The Department of Industrial Engineering, Faculty of Engineering, Rajamangala University of Technology Lanna and Materials and Manufacturing Research Center, Faculty of Engineering, Rajamangala University of Technology Lanna is also acknowledged.