Low-Temperature Sintering and Piezoelectric Properties of CuO-Added KNbO3 Ceramics

Abstract

Dielectric and piezoelectric properties of CuO-added KNbO3 (KN) ceramics were investigated. The CuO reacted with the Nb2O5, formed a CuO-Nb2O5-related liquid phase during the sintering, and assisted the densification of the KN ceramics at low temperatures. Moreover, some of the Cu2+ ions replaced the Nb5+ ions in the matrix and behaved as a hardener. The dielectric and piezoelectric properties of the KN ceramics were considerably influenced by the relative density. The 1.0mol% CuO-added KN ceramic sintered at 960 degrees C for 1.0h, which showed a maximum relative density, exhibited a high phase angle of 86.9 degrees, P-r of 14.8C/cm(2), and E-c of 1.8kV/mm. This specimen also exhibited good dielectric and piezoelectric properties: epsilon(T)(33)/epsilon(o) of 364, d(33) of 122pC/N, k(p) of 0.29, and Q(m) of 611.