Effects of A-Site Equivalence and Non-Equivalence Substitution on Structure and Electric Properties of K_0.5Na_0.5NbO₃ Lead-Free Piezoelectric Ceramics

Abstract:

For Na0.5K0.5NbO3(KNN)-based lead-free piezoelectric ceramics, an important phenomenon was found that the piezoelectric properties can be improved remarkably for equivalence substitution while it can’t be improved remarkably for non-equivalence substitution. To find out the real reason for this phenomenon, Li+ and La3+ were used to modify KNN lead-free piezoelectric ceramics by conventional sintering technique. The relaxor characteristic was detected for La3+ modified KNN lead-free piezoelectric ceramics, and this caused low piezoelectric properties. However, the relaxor characteristic can not be detected for Li+ modified KNN lead-free piezoelectric ceramics, and the piezoelectric properties is higher than that of La3+ modified KNN lead-free piezoelectric ceramics. Accordingly, the relaxor characteristic has important effect on structure and electric properties. The results show that equivalence and non-equivalence substitution have important and different effect on structure and performance of KNN ceramics.

• Periodical: Advanced Materials Research (Volume 627)
• Pages: 687-693
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.627.687
• Online since: December 2012
• Authors: Hong Mei Zhang, Jing Bo Zhao, Shao Bo Qu, Hong Liang Du
• Keywords: Equivalence and Non-Equivalence Substitution, K_0.5Na_0.5NbO₃, Lead-Free Ceramics, Piezoelectric

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