Potassium Sodium Niobate-Based Lead-Free Piezoelectric Multilayer Ceramics Co-Fired with Nickel Electrodes

Materials

Shinichiro Kawada¹  Hiroyuki Hayashi¹  Hideki Ishii¹  Masahiko Kimura²  Akira Ando²  Suetake Omiya²  Noriyuki Kubodera² 

[1] Murata Manufacturing Co., Ltd., Nagaokakyo, Kyoto 617-8555, Japan

关键词: ferroelectric material;    potassium sodium niobate;    (K;    Na)NbO₃;    piezoelectric actuator;    base metal inner electrode;    multilayer structure;   

DOI  :  10.3390/ma8115389

来源: mdpi

【 摘 要 】

Although lead-free piezoelectric ceramics have been extensively studied, many problems must still be overcome before they are suitable for practical use. One of the main problems is fabricating a multilayer structure, and one solution attracting growing interest is the use of lead-free multilayer piezoelectric ceramics. The paper reviews work that has been done by the authors on lead-free alkali niobate-based multilayer piezoelectric ceramics co-fired with nickel inner electrodes. Nickel inner electrodes have many advantages, such as high electromigration resistance, high interfacial strength with ceramics, and greater cost effectiveness than silver palladium inner electrodes. However, widely used lead zirconate titanate-based ceramics cannot be co-fired with nickel inner electrodes, and silver palladium inner electrodes are usually used for lead zirconate titanate-based piezoelectric ceramics. A possible alternative is lead-free ceramics co-fired with nickel inner electrodes. We have thus been developing lead-free alkali niobate-based multilayer ceramics co-fired with nickel inner electrodes. The normalized electric-field-induced thickness strain (S_max/E_max) of a representative alkali niobate-based multilayer ceramic structure with nickel inner electrodes was 360 pm/V, where S_max denotes the maximum strain and E_max denotes the maximum electric field. This value is about half that for the lead zirconate titanate-based ceramics that are widely used. However, a comparable value can be obtained by stacking more ceramic layers with smaller thicknesses. In the paper, the compositional design and process used to co-fire lead-free ceramics with nickel inner electrodes are introduced, and their piezoelectric properties and reliabilities are shown. Recent advances are introduced, and future development is discussed.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.