Giant Piezoelectric Coefficient in Lead-Free BiFe0.975Ti0.025O3–CaTiO3 Solid Solution Thin Films

• Published in: Crystal growth & design Vol. 21; no. 11; pp. 6230 - 6236
• Main Authors: Shu, Mingfang, Yang, Bingbing, Liu, Miao, Zhu, Shunjin, Li, Sumei, Pan, Chengbing, Wang, Jiamingzhu, Yin, Lihua, Yang, Jie, Zhu, Xuebin, Sun, Yuping
• Format: Journal Article
• Language: English
• Published: American Chemical Society 03.11.2021
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/acs.cgd.1c00697

Searching for lead-free piezoelectric thin films with a high piezoelectric coefficient is beneficial for applications in microelectromechanical systems. The solid solution method is verified as an effective route to largely improve the piezoelectric performance. Herein, we report the piezoelectric properties in polycrystalline (1 – x)­BiFe0.975Ti0.025O3–xCaTiO3 thin films. A giant effective piezoelectric coefficient of 542 pm/V has been achieved in 0.76BiFe0.975Ti0.025O3–0.24CaTiO3 thin films because of the enhanced dielectric constant as well as remanent polarization, which originated from the coexistence of rhombohedral and pseudo-cubic phases and enhanced growth kinetics. The results indicate a type of lead-free piezoelectric thin film based on BiFeO3 with the effective piezoelectric coefficient larger than 500 pm/V.