Electrical Properties of La-Doped Ba_0.7Ca_0.3TiO₃ Lead-Free Ceramics

Abstract

(Ba_0.7Ca_0.3)_1-1.5xLa_xTiO₃ ceramics with x = 0 – 0.03 were prepared using a solid state sintering method. Upon La³⁺ increasing content, tetragonality of doped ceramics decreased. The intrinsic contribution affected piezoelectric coefficient decrement. The changes in dielectric loss, remanent polarization, coercive field, planar electromechanical coupling coefficient and mechanical quality factor seemed to be correlated with the extrinsic contribution from domain wall mobility. La³⁺ addition caused both grain size reduction and dielectric constant enhancement. The results here suggested that BCT electrical properties' dependence on La³⁺ substitution may be useful for ferroeletric devices.

Keywords:

• La doping
• tetragonality
• domain wall motion
• donor doping

Acknowledgments

We acknowledge W. Meevasana for helpful discussions.

Funding

This work is financially supported by the Thailand Research Fund (TRF) through the Royal Golden Jubilee Ph.D. program and the National Research University Project under Thailand's Office of the Higher Education Commission (OHEC).