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CaTiO 3 ‐Modified (K 0.50 Na 0.50 )(Nb 0.96 Sb 0.04 )O 3 Lead‐Free Piezoelectric Ceramics

2008; Wiley; Volume: 91; Issue: 10 Linguagem: Inglês

10.1111/j.1551-2916.2008.02542.x

1551-2916

Jiagang Wu, Dingquan Xiao, Yuanyu Wang, Wenjuan Wu, Bin Zhang, Jianguo Zhu,

Microwave Dielectric Ceramics Synthesis

(1− x )(Na 0.5 K 0.5 )(Nb 0.96 Sb 0.04 )O 3 – x CaTiO 3 lead‐free piezoelectric ceramics were prepared by normal sintering. The effects of the CaTiO 3 on the phase structure and piezoelectric properties of the ceramics were systematically studied. These results show that the CaTiO 3 ‐modified (K 0.50 Na 0.50 )(Nb 0.96 Sb 0.04 )O 3 lead‐free piezoelectric ceramics form stable solution with orthorhombic structure, and the Curie temperature and the polymorphic phase transition of the ceramics decreased with increasing x . Moreover, the effect of the polarization temperature ( T p ) on the piezoelectric properties of the ceramics was also discussed. The result shows that the piezoelectric properties of the ceramics strongly depend on the T p . The ceramics with x =0.01 poled at T p =35°C possess optimum properties ( d 33 =168 pC/N, k p =45%, T c =314°C, T o − t =120°C, ɛ r ∼1041, and tan δ∼2.5%). These results indicate that the ceramic is a promising candidate material for lead‐free piezoelectric ceramics.