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Synthesis of KNbO 3 Piezoelectric Ceramics Using Citrate Precursors

2008; Institute of Physics; Volume: 47; Issue: 9S Linguagem: Inglês

10.1143/jjap.47.7669

1347-4065

Ken‐ichi Kakimoto, Takeshi Ito, Hitoshi Ohsato,

Acoustic Wave Resonator Technologies

An aqueous-based citrate precursor route has been adopted for the synthesis of KNbO3 nanopowders. The required amount of KNO3 or C6H5O7K3·H2O solution was mixed with citric Nb solution to form white precipitates, followed by heat treatment at 800 °C to produce KNbO3 nanopowders with an average particle size of 250–300 nm. The as-received nanopowder showed a well-sinterable property without using any additives, and the obtained KNbO3 ceramics showed saturated ferroelectric hysteresis loops of Pr = 22.9 µC/cm2 and Ec = 7.8 kV/cm at 1 Hz. The excellent piezoelectric properties of kp = 0.35, Qm = 131, k31 = 0.23, d31 = -31 pC/N, and d33 = 110 pC/N were obtained for KNbO3 ceramics derived from KNO3 solution, whereas kp = 0.29, Qm = 96, k31 = 0.20, d31 = -45 pC/N, and d33 = 115 pC/N were obtained for KNbO3 ceramics derived from C6H5O7K3·H2O solution.