Superior piezoelectricity and rhombohedral-orthorhombic-tetragonal phase coexistence of (1 − x)(K, Na)(Nb, Sb)O3−x(Bi, Na)HfO3 ceramics. (February 2020)

• Record Type: Journal Article
• Authors: Zhang, Jialiang; Sun, Xue; Su, Wenbin; Yao, Weizeng; Zhou, Chunming
• Is Part Of: Scripta materialia. Number 176(2020)
• Page Start: 108
• Page End: 111
• Publication Date: 2020-02
• Subjects: Lead-free materials -- KNN-based ceramics -- Rhombohedral-orthorhombic-tetragonal phase coexistence -- Superior piezoelectricity -- X-ray diffraction; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2019.09.017
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: Requirements for lead-free piezoelectric ceramics are growing increasingly strong owing to environmental concerns. This paper reports the study results of (1 − x )(K0.48 Na0.52 )(Nb0.96 Sb0.04 )O3 – x (Bi0.50 Na0.50 )HfO3 ceramics. It was found that all the ceramics with 0.035 ≤ x ≤ 0.047 show rhombohedral−orthorhombic−tetragonal ( R − O − T ) phase coexistence at room temperature and the one with x = 0.045 has a giant piezoelectric coefficient d 33 of 540 pC/N. Unexpectedly, the rhombohedral−orthorhombic phase transition temperature is almost independent of the (Bi0.50 Na0.50 )HfO3 content. Moreover, electromechanical coupling factor k p is temperature-stable in orthorhombic phase. The results demonstrate that superior piezoelectricity can be obtained in a (K, Na)NbO3 -based ceramic of R − O − T phase coexistence. Graphical abstract: Image, graphical abstract