title: Sintering and piezoelectric properties of KNN ceramics doped with KZT.
abstract: This paper investigates the effect of K(1.94)Zn(1.06)Ta(5.19)O(15) (KZT) addition on the sintering behavior and piezoelectric properties in lead free piezoelectric ceramics of (K(0.5)Na(0.5))NbO(3) (KNN). The apparent density of sintered KNN ceramics was increased with KZT addition, and a relative density of above 96.3% was obtained with the doping of over 0.5 mol% KZT. The maximum dielectric and piezoelectric properties of epsilon(T)(3)/epsilon(0) = 590, d(33) = 126 pC/N, k(p) = 0.42, and P(r) = 18 microC/cm(2) were obtained from 0.5 mol% KZT-doped KNN ceramics. A small amount of KZT (about 0.5 mol%) was effective for improving the sintering behavior and piezoelectric properties, but KZT addition exceeding 1.0 mol% was effective only for densification. A small amount of KZT was effective for densification of KNN ceramics by promoting K(5.75)Nb(10.8)O(30) liquid phase formation. However, even though KNN with 1.0 to approximately -2.0 mol% KZT had a relative density of >98.5%, the piezoelectric properties were inferior to those of 0.5 mol% KZT-doped KNN, presumably due to the smaller grain size and excess liquid phase of the KNN ceramics doped with higher amounts of KZT. It is believed that a small amount of KZT could be one of the suitable sintering aids to obtain highly dense KNN based piezoelectric.
authors.affiliation: Center for Future Technology, Korea Institute of Materials Science, Changwon, Kyungnam, Korea. jhryu@kims.re.kr
authors.forename: Jungho
authors.initials: J
authors.lastname: Ryu
authors.forename: Jong-Jin
authors.initials: JJ
authors.lastname: Choi
authors.forename: Byung-Dong
authors.initials: BD
authors.lastname: Hahn
authors.forename: Dong-Soo
authors.initials: DS
authors.lastname: Park
authors.forename: Woon-Ha
authors.initials: WH
authors.lastname: Yoon
authors.forename: Kun-Young
authors.initials: KY
authors.lastname: Kim
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D002516:Ceramics / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D017097:Electric Impedance; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006358:Hot Temperature; D007854:Lead / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014025:Titanium / Q000737:chemistry*; D014159:Transducers; D015040:Zirconium / Q000737:chemistry*
chemical_list: C065536:lead titanate zirconate; D007854:Lead; D015040:Zirconium; D014025:Titanium