Influence of Calcination Temperature on Structure-Property Relationship in BCZT Lead-Free Piezoceramic

Abstract

Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃ or BCZT has become a promising lead-free piezoelectric candidate, since it was observed that it has a large piezoelectric coefficient. To synthesize the BCZT ceramic, a conventional solid-state reaction is a simple and low-cost method. However, calcination temperature plays a significant role on the chemical reaction of the starting materials. Therefore, this work aims to study the impacts of calcination temperature on the crystal structure, microstructure and functional properties of the BCZT ceramic prepared by solid-state reaction. This is in order to improve understanding of processing-structure-property relationships of this material. The BCZT powders were calcined at 1100 °C to 1300 °C for 3 h. Then, the calcined powders were pressed into a disk shape before sintering at 1400 °C for 3 h. Full-pattern refinement showing the coexistence of orthorhombic-tetragonal phases was observed. In addition, the particle size distribution gradually shifted to larger sizes as calcination temperature increased. However, the occurrence of inter-particle necking was observed when the calcination temperature as increased to 1300 °C, giving a sudden increase in particle size as well as a less sinter-active powder that consequently led to the presence of the smallest grain size in the ceramic. As a result, the lowest values of dielectric permittivity as well as the lowest polarization were observed for the BCZT ceramic made from the powder calcined at 1300 °C. This work found that calcination temperature played a crucial role on the observed microstructure in the BCZT ceramics, which strongly influenced its electrical properties.

KEYWORDS:

• Lead-free piezoceramics
• BCZT ceramic
• calcination temperature
• dielectric properties
• ferroelectric properties

Acknowledgments

The authors gratefully acknowledge the financial support provided by Faculty of Science and Technology, Thammasat University, Contract No. Sci GR39/2563. In addition, we thank to Prof. Dr. Naratip Vittayakorn, Advanced Materials Research Unit, Department of Chemistry, Faculty of Science, King Mongkut’s Institute of Technology Ladkrabang, Thailand for supporting on electrical measurements. Lastly, a sincere thank you to Dr. Rory Hulse for proofreading this article.