Enhanced sinterability and electrical properties of Bi₂O₃-added Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃ ceramics

ABSTRACT

The ceramics of Bi₂O₃-added Ba_0.85Ca_0.15Zr_0.1Ti_0.9O₃ or BCZT-xBi (where x = 0.005, 0.01, 0.02 and 0.1 mol fraction) were fabricated from sol-gel auto-combustion derived BCZT and commercial Bi₂O₃ powders. In this study, BCZT-0.02Bi ceramic sintered at 1200°C for 2 h was found to be the optimum composition with high relative density and homogeneous microstructure. The temperature at maximum dielectric constant (T_max) of this sample was near room temperature, rendering a high dielectric constant value (∼1653). Frequency dependence of T_max suggested the relaxor behavior which was also supported by slim ferroelectric hysteresis loops. Since a relatively large breakdown voltage (> 70 kV/cm) was observed, the BCZT-0.02Bi ceramic could be a potential lead-free electrostrictive/piezoelectric material for actuator applications.

Acknowledgment

PJ would like to thank Asst. Prof. Soodkhet Pojprapai for the equipments in this work.

Funding

This work was financially supported by the Thailand Research Fund (IRG5780013) and Center of Excellence in Materials Science and Technology, the Faculty of Science, the Graduate School and Chiang Mai University. Partial funding from Thailand Institute of Scientific and Technological Research and Center of Excellence in Physics and Astronomy are also acknowledged. PJ would like to thank the financial support from the CMU 50^th Anniversary Ph.D. Grant from Chiang Mai University (PHD/018/2556).