Fabrication of Dense KNbO3 Ceramics Derived from KHCO3 as a Starting Material

Potassium niobate-based ceramics, K(1+x)NbO3 (KN-10000x, x = 0-0.001), were fabricated using KHCO3 powder as a starting material to improve their reproducibility. The KN-7.2 ceramics all had high relative density ratios exceeding 96% and resistivities of above 10(12) Omega.cm. Additionally, many KN-7.2 ceramics were prepared under different levels of humidity of about similar to 70% in the weighing process. The relative density ratios of all the KN-7.2 ceramics were similar, showing the excellent reproducibility obtained using KHCO3 powder as a starting material. The electromechanical coupling factor k(33) and piezoelectric strain constant d(33) of the KN-7.2 ceramics were 0.50 and 90 pC/N, respectively. (C) 2012 The Japan Society of Applied Physics