Phase structure and electrical properties of strontium modified (Na0.48-xK0.48-xLi0.04Srx)Nb0.89Ta0.05Sb0.06O3ceramics

✍ Scribed by Zheng, Limei ;Wang, Jinfeng ;Ming, Baoquan ;Wang, Chunming ;Du, Juan ;Wu, Qingzao

• Book ID: 105365080
• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 399 KB
• Volume: 206
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200824326

✦ Synopsis

Abstract

(Na~0.48–x~ K~0.48–x~ Li~0.04~Sr__~x~)Nb~0.89~Ta~0.05~Sb~0.06~O~3~ (abbreviated as NKLSr~x~__ NST) lead‐free ceramics are fabricated by conventional solid state reaction. The material with perovskite structure contains both tetragonal and orthorhombic phases at room temperature when x ≤ 0.02, and it changes into cubic phase gradually as x increases. A second phase KSr~2~Nb~5~O~15~ begins to appear at x = 0.03 and becomes obvious with increasing Sr content. Dielectric studies show that the Sr^2+^ modification lowers the Curie temperature and induces the diffuseness of cubic–tetragonal phase transition. The addition of Sr^2+^ improves the density and piezoelectric properties of NKLNST. The ceramic modified with 0.008 mol SrO shows the optimum piezoelectric properties (d~33~ = 278 pC/N, k~p~ = 0.504, tan δ = 0.025). Degradation of k~p~ is found after the first thermal cycling due to the tetragonal–orthorhombic phase transition near room temperature. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)