Dense Li/Ta-codoped KNN-based piezoceramics with d(33)* up to 375 pm/V were successfully fabricated by conventional sintering at a temperature as low as 900 degrees C by using LiF as a sintering additive. The reduction of densification temperature up to 200 degrees C was realized by a transient liquid phase sintering mechanism, consequently no grain boundary phase was observed in the sintered samples. It was found that the addition of LiF could further shift down the tetragonal orthorhombic transition point (TT-O), indicating that a small amount of Li+ could diffuse into the A-site of KNN matrix. The introduction of LiF enhanced the linearity of strain curves of the ceramics, which is unambiguously in favor for the actuator application. The present work reveals that low-temperature sintered LiF-doped KNN-based piezoceramics demonstrates promising potential in multilayer-structured actuator applications. (C) 2013 Elsevier Ltd. All rights reserved.
1.Tsinghua Univ, State Key Lab New Ceram & Fine Proc, Sch Mat Sci & Engn, Beijing 100084, Peoples R China 2.Chinese Acad Sci, Inst Opt & Elect, Chengdu 610209, Peoples R China
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