Phase transitions and electrical properties of (1−x)(K0.5Na0.5)NbO3−xBiScO3 lead-free piezoelectric ceramics with a CuO sintering aid

✍ Scribed by Xuhai Li; Meng Jiang; Jing Liu; Jiliang Zhu; Xiaohong Zhu; Lihua Li; Yu Zhou; Jianguo Zhu; Dingquan Xiao

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 783 KB
• Volume: 206
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200925036

✦ Synopsis

Abstract

(1−x)(K~0.5~Na~0.5~)NbO~3~−__x__BiScO~3~ doped with 1 mol% CuO (KNN‐BS‐Cu‐x) lead‐free piezoelectric ceramics were prepared by the solid state reaction technique. With the CuO doping, all the ceramics can be well sintered at 1090–1150 °C and exhibit a perovskite structure. After the substitution of BiScO~3~, the polymorphic phase transition (PPT) was shifted to near room temperature; besides, the cubic–tetragonal phase transitions were also shifted to lower temperatures and a relaxor behavior was induced. The ceramic (x = 0.018) with PPT near room temperature exhibited excellent electrical properties (d~33~ = 224 pC/N, k~p~ = 0.40, and T~C~ = 331 °C). A relatively high mechanical quality factor (288) was also obtained in this particular composition. All these results reveal that KNN‐BS‐Cu‐x ceramics may become promising candidates for lead‐free piezoelectric materials.