Enhanced Temperature Stability and Defect Mechanism of BNT‐Based Lead‐Free Piezoceramics Investigated by a Quenching Process. (20th December 2018)

• Record Type: Journal Article
• Authors: Li, Zhi‐Tao; Liu, Hui; Thong, Hao‐Cheng; Xu, Ze; Zhang, Mao‐Hua; Yin, Jie; Li, Jing‐Feng; Wang, Ke; Chen, Jun
• Is Part Of: Advanced Electronic Materials. Volume 5:Number 3(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-12-20
• Subjects: defect mechanism -- depolarization temperature -- lead‐free BNT -- quenching; Materials -- Electric properties -- Periodicals; Materials science -- Periodicals; Magnetic materials -- Periodicals; Electronic apparatus and appliances -- Periodicals; 537
• DOI: 10.1002/aelm.201800756
• Languages: English
• ISSNs: 2199-160X

Abstract

Abstract: Because of the environmental concerns of eliminating lead from piezoelectric products, bismuth‐based perovskite is becoming one of the most potential candidates. However, its relatively low thermal depolarization temperature ( Td ) is still an imperative obstacle hindering implementation of this material for practical application. Here, an enhanced temperature stability of 0.94(Bi0.5 Na0.5 )TiO3 ‐0.06BaTiO3 (BNTBT6) piezoceramics is reported, which can be obtained by the effective quenching process. Quenching process enhances the depolarization temperature to 136 °C, which is 40 °C higher than that of normal sintered samples. By using X‐ray photoelectron spectroscopy and electron paramagnetic resonance methods, it is revealed that oxygen vacancy may exist in the quenched samples and consequently pins the domain walls, resulting in significant enhancement of depolarization temperature. Temperature‐dependent dielectric, piezoelectric, and ferroelectric behaviors are measured as criteria to evidence the enhanced temperature stability. Abstract : A quenching and annealing process is used to systematically investigate the depolarization temperature of 0.94(Bi0.5 Na0.5 )TiO3 ‐0.06BaTiO3 lead‐free piezoceramics. Oxygen vacancy, which is proved by X‐ray photoelectron spectroscopy and electron paramagnetic resonance measurements, may mainly contribute to the enhanced depolarization temperature. Structure evolution is also investigated. This work definitely sheds light on possible alternatives of increasing temperature stability of (Bi0.5 Na0.5 )TiO3 ‐based piezoelectric ceramics.