Morphotropic phase boundary, polymorphic phases and enhanced electrostrain/piezoelectricity in Ag1-xKxNbO3 solid-solution ceramics. Issue 10 (August 2023)

• Record Type: Journal Article
• Authors: Tian, Ye; Jia, Ye; Wang, Xinyi; Li, Lei; Geng, Jia; Wang, Tong; Xu, Yonghao; Jin, Li; Bao, Yizheng; Chen, Chen; Zhang, Leiyang; Ma, Ming; Wei, Xiaoyong; Ge, Wanyin
• Is Part Of: Journal of the European Ceramic Society. Volume 43:Issue 10(2023)
• Page Start: 4395
• Page End: 4407
• Publication Date: 2023-08
• Subjects: AgNbO3 -- MPB -- Piezoelectric -- Electrostrain -- Monoclinic -- Polymorphic; 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.2023.03.031
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: Ag1− x K x NbO3 (AKN x ( x ≤ 0.12) ceramics were prepared to understand the relationship of structure-properties driven by compositions and temperatures. The results suggested that this binary system possessed a morphotropic phase boundary (MPB) consisted of ferrielectric and ferroelectric phases with iso-symmetry at room temperature, in which domains switching together with electric-field-induced irreversible phase transition achieved a much higher electrostrain ( S max = 0.4%) than other compositions. But this MPB was destroyed after poling, leading to inferior piezoelectricity. A phase diagram was drawn after analyzing in situ XRD and dielectric data, where an almost vertical ferrielectric/antiferroelectric ↔ polymorphic ferroelectric MPB line starting from a triple point was proposed. As temperature increased, the piezoelectricity significant enhanced near ferroelectric orthorhombic ↔ monoclinic phase boundary, while the highest piezoelectricity was achieved near the monoclinic ↔ paraelectric phase boundary with d 33 = 200 pC/N. The enhanced piezoelectricity is intimately related to the ferroelectric monoclinic possessing Pm symmetry.