Preparation and Electric Property of Lead-Free KNbO₃ Piezoceramics Derived from Citrate Complex Precursor

Abstract

The synthesis of well-crystalline KNbO ₃ nanopowder has been carried out by using citrate complex precursor method. By using this powder as raw materials, dense KNbO ₃ ceramics (RD = 98.9%) was successfully prepared, and showed excellent ferroelectric and piezoelectric properties. The effect of starting K/Nb mixture ratio in aqueous precursor solution on the crystallinity and electric properties of derived KNbO ₃ ceramics was studied. It was found that an appropriate superfluous addition of the K-souce (K/Nb = 1.05) was required to synthesis excellent KNbO ₃ ceramics, because of the existence of residual K⁺ ions in the aqueous solution without being involved in the formation of the chelating complex.

Keywords:

• Lead-free piezoelectrics
• KNbO₃
• citrate precursor
• nanopowder
• P-E hysteresis curve

Acknowledgment

This research was supported by the Industrial Technology Research Grant Program in 2007 from the New Energy and Industrial Technology Development Organization (NEDO) of Japan