Dielectric and piezoelectric properties of (K^sub 0.5^Na^sub 0.5^)(Nb^sub 0.97^Sb^sub 0.03^)O3 ceramics doped with Bi^sub 2^O3

• Published in: Journal of electroceramics 2012-10, Vol.29 (2), p.144
• Main Authors: Noh, Jungrae, Yoo, Juhyun
• Format: Article
• Language: English
• ISSN: 1385-3449; 1573-8663
• DOI: 10.1007/s10832-012-9744-1

In this study, to develop the optimal composition of ceramics for low loss piezoelectric actuator and ultrasonic motor applications, (K^sub 0.5^Na^sub 0.5^)(Nb^sub 0.97^Sb^sub 0.03^)O3+0.009 K^sub 5.4^Cu^sub 1.3^Ta^sub 10^O^sub 29^+0.1wt%Li^sub 2^CO3+xwt%Bi^sub 2^O3(x=0~0.9) lead-free piezoelectric ceramics with a fixed quantity of 0.009 K^sub 5.4^Cu^sub 1.3^Ta^sub 10^O^sub 29^ (abbreviated as KCT) were manufactured using the conventional solid-state solution processes. The effects of Bi^sub 2^O3 addition on the dielectric and piezoelectric properties were then investigated. From the X-ray diffraction analysis result the specimens demonstrated orthorhombic symmetry when Bi^sub 2^O3 was less 0.6 wt%, a pseudo-cubic phase appeared when Bi^sub 2^O3 was 0.9 wt%. SEM images indicate that a small amount of Bi^sub 2^O3 addition affect the microstructure. The piezoelectric properties of (K^sub 0.5^Na^sub 0.5^)(Nb^sub 0.97^Sb^sub 0.03^)O3 ceramics were greatly improved by a certain amount of Bi^sub 2^O3 addition. Excellent properties of density=4.54 g/cm^sup 3^, relative densities=98.5 %, k ^sub p^=0.468, Q ^sub m^=1,715 and d ^sub 33^=183 pC/N were obtained with a composition of 0.3 wt% Bi^sub 2^O3 [PUBLICATION ABSTRACT]