Gigantic Electrostrain in Duplex Structured Alkaline Niobates

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• 作者：Si-Young Choi ; Soon-Jong Jeong ; Dae-Su Lee ; Min-Soo Kim ; Jae-Shin Lee ; Jeong Ho Cho ; Byoung Ik Kim ; Yuichi Ikuhara
• 刊名：Chemistry of Materials
• 出版年：2012
• 出版时间：September 11, 2012
• 年：2012
• 卷：24
• 期：17
• 页码：3363-3369
• 全文大小：645K
• 年卷期：v.24,no.17(September 11, 2012)
• ISSN：1520-5002

文摘

We demonstrate that an exceptionally large strain can be induced in CaZrO₃-modified alkaline-niobates by electric fields. The maximum induced strain of our niobate-based ceramics could reach more than 1,000 pm/V, which is a much higher value than that of commercial soft PZT ceramics. Atomic-scale annular bright-field (ABF) and annular dark-field (ADF) scanning transmission electron microscopy (STEM) directly revealed that individual single grains were composed of an electrically duplex core鈥搒hell structure; relaxor-like cores and paraelectric shells. Based on this ABF STEM analysis along with electrical measurements, a plausible mechanism explaining the high strain effect in the present work was suggested. This new material offers an unprecedented opportunity to produce efficient Pb-free piezoelectrics for applications that require large electrostrictive motion.

Keywords:

core/shell; perovskites; electron microscopy; electric field induced strain; actuator