High electrostrictive effect in La3+-doped Ba(Zr0.2Ti0.8)O3 lead-free ferroelectrics

Abstract Perovskite ferroelectric ceramics with T m (temperature corresponding to maximum dielectric permittivity e ′) around room temperature and high electrostrictive coefficient Q 33 are of interest to the applications in high-precision actuators, since low-hysteresis/non-hysteresis and high strain response can be generated in these materials based on a purely electrostrictive effect. In this work, undoped Ba(Zr 0.2 Ti 0.8 )O 3 (BZT) and La 3+ -doped Ba(Zr 0.2 Ti 0.8 )O 3 (BLZT) lead-free ferroelectrics were synthesized by solid state reaction method. Their dielectric and ferroelectric properties were investigated systematically with an emphasis on electrostrictive effect. With respect to increase of La 3+ content from 0 to 1%, the T m of BLZT decreases from 44.5 °C to 14.6 °C, and the diffuseness degree γ increases from 1.814 to 1.993. A conductive mechanism, which is prominent in undoped BZT, is inhibited drastically by introducing the La 3+ into BZT. A high electrostrictive strain of 0.08% and a low hysteresis η ( x  = 0.25% composition at room temperature. The Q 33 ranges from 0.0377 m 4 /C 2 and 0.0537 m 4 /C 2 . This work not only reports a high electrostrictive effect in BLZT ferroelectrics, but also provides BLZT ceramics with a potential application in high-precision actuators.