Effects of Low Concentration BiFeO3 Additions on Microstructure and Piezoelectric Properties of (K0.5Na0.5)NbO3 Ceramics
(1- x) K0.5Na0.5NbO3 – x BiFeO3 lead-free piezoelectric ceramics were prepared by the conventional ceramic processing. The compositional dependence of the phase structure and the electrical properties of the ceramics were studied. A morphotropic phase boundary (MPB) between the orthorhombic and tetragonal phases was identified in the composition range of x = 0.01. The ceramics exhibit a strong compositional dependence and enhanced piezoelectric properties. The ceramics with 0.6 mol.% BF exhibit good electrical properties (d33 ～146 pC/N, kp ～51%, Tc ～405°C, To-t ～185 °C, εr ～432, and tan θ～ 4.60 %. The related mechanism of the enhanced electrical properties of the ceramics was also discussed. These results show that the air-sintered (1−x) KNN− x BF (0.006 < x < 0.01) ceramic is a promising lead-free piezoelectric material.
Yun-Hae Kim, Prasad Yarlagadda, Xiaodong Zhang and Zhijiu Ai
P. Xu et al., "Effects of Low Concentration BiFeO3 Additions on Microstructure and Piezoelectric Properties of (K0.5Na0.5)NbO3 Ceramics", Advanced Materials Research, Vols. 335-336, pp. 968-975, 2011