Coexistence of three ferroelectric phases and enhanced piezoelectric properties in BaTiO3–CaHfO3 lead-free ceramics. Issue 2 (February 2018)

• Record Type: Journal Article
• Authors: Yang, Yang; Zhou, Yibei; Ren, Juan; Zheng, Qiaoji; Lam, Kwok Ho; Lin, Dunmin
• Is Part Of: Journal of the European Ceramic Society. Volume 38:Issue 2(2018)
• Page Start: 557
• Page End: 566
• Publication Date: 2018-02
• Subjects: Barium titanate -- Phase transition -- Coexistence of three ferroelectric phases -- Piezoelectric properties; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2017.09.023
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: Perovskite ferroelectrics possess the fascinating piezoelectric properties near a morphotropic phase boundary, attributing to a low energy barrier that the results in structural instability and easy polarization rotation. In this work, a new lead-free system of (1- x )BaTiO3 - x CaHfO3 was designed, and characterized by a coexistence of ferroelectric rhombohedral-orthorhombic-tetragonal ( R-O-T ) phases. With the increase amount of CaHfO3 ( x ), a stable coexistence region of three ferroelectric phases ( R-O-T ) exists at 0.06 ≤ x ≤ 0.08. Both large piezoelectric coefficient ( d 33 ∼400 pC/N), inverse piezoelectric coefficient ( d 33 * ∼547 pm/V) and planar electromechanical coupling factor ( k p ∼58.2%) can be achieved for the composition with x = 0.08 near the coexistence of three ferroelectric phases. Our results show that the materials with the composition located at a region where the three ferroelectric R-O-T phases coexist would have the lowest energy barrier and thus greatly promote the polarization rotation, resulting in a strong piezoelectric response.