Temperature stability of sodium-doped BiFeO3–BaTiO3 piezoelectric ceramics

Abstract

An enhancement in piezoelectric properties of lead-free ceramic materials by compositional engineering is often accompanied by a sacrifice in the temperaturestability of properties. Here we demonstrate that high piezoelectric properties and excellent high-temperature stability are obtained simultaneously in 0.72BiFeO 3 -0.28Ba 1-x Na x TiO 3 (BF-BTNx, x = 0-0.035) ceramics. Our results show that the high temperature-stable piezoelectric properties from 26 to 470°C, combined with room temperature high piezoelectric constant d 33 = 165pC/N and electromechanical coupling factor k p = 0.35 are achieved for x = 0.015 BF-BTNx ceramics. The results suggest Na-doped BF-BT system ceramic is a potential candidate for high temperature harsh environments actuators and sensors applications.

A Review of a Good Binary Ferroelectric Ceramic: BaTiO3–BiFeO3

“…Doping or substitution, such as Al, Na, Bi 0.5 Na 0.5 TiO 3 , La­(Mg 0.5 Ti 0.5 )­O 3 , and MnO 2 –CuO, could increase the temperature stability or insulating properties of BTO–BFO. ,,− The universal core–shell microstructures in this system could also increase thermostability . The addition of Na could enhance the Curie temperature of BTO–BFO Table includes the structural parameters of x BTO–(1– x )­BFO.…”

“…99 The addition of Na could enhance the Curie temperature of BTO−BFO. 123 Table 1 includes the structural parameters of xBTO−(1−x)BFO. It shows a diffuse phase transition when the molar fraction of BTO is 10% and 20%.…”

“…Besides, bismuth gallium oxide (BiGaO 3 ) is a typical perovskite ferroelectric. Because of its lone electron pairs, its ferroelectric polarization and piezoelectric response are bigger than in the case of BTO. − The introduction of BiGaO 3 can improve the thermostability and piezoelectricity of BTO–BFO ceramics without changing its T c . ,− …”

“…BTO–BFO ceramics with pseudocubic or a combination of pseudocubic and rhombohedral phases are less thermally stable than those with rhombohedral phases . Doping or substitution, such as Al, Na, Bi 0.5 Na 0.5 TiO 3 , La­(Mg 0.5 Ti 0.5 )­O 3 , and MnO 2 –CuO, could increase the temperature stability or insulating properties of BTO–BFO. ,,− The universal core–shell microstructures in this system could also increase thermostability . The addition of Na could enhance the Curie temperature of BTO–BFO …”

Lead-Free BiFeO3–BaTiO3 Ceramics: An Overview

“…In the case of a pure BTO-BFO system, the Curie temperature is 804 K, which can be varied by altering the BTO/BFO molar ratio [30,44]. Rhombohedral phases in BTO-BFO are thermally stable in comparison to pseudocubic or a mixture of rhombohedral and pseudocubic phases [59]. Substitution of ions like Na, Al, Bi 0.5 Na 0.5 TiO 3 , MnO 2 -CuO, and La(Mg 0.5 Ti 0.5 )O 3 is used to enhance the insulating properties as well as the thermal stability of BTO-BFO [57,[60][61][62][63].…”