Seminars

  • High-Performance Lead-Free Piezoceramics with High Curie Temperatures

  • Speaker : Myang Hwan Lee
    Affiliation : School of Materials Science and Eng., Changwon National University
    Date : May 10, 2018 1:30 PM
    Place : Building 108 Room 901
    Contact : ysoh@unist.ac.kr
    Host : Yoon Seok Oh
  • Abstract

  • Myang Hwan Lee1, Da Jeong Kim1, Jin Su Park1, Sang Wook Kim1, Tae Kwon Song1,* Myong-Ho Kim1, Won-Jeong Kim2, Dalhyun Do3, and Il-Kyoung Jeong4

    1School of Materials Science and Eng., Changwon Nat’l Univ., Gyeongnam 51140, Korea
    2Department of Physics, Changwon Nat’l Univ., Gyeongnam 51140, Korea.
    3Department of Advanced Materials Eng., Keimyung University Daegu 42403, Korea
    4Department of Physics, Pusan Nat’l Univ., 46241, Korea

    Recently lead-free piezoelectric ceramics are extensively studied with respect to morphotropic phase boundary (MPB) where good piezoelectric properties are observed. Around MPB in bismuth ferrite (BiFeO3) and barium titanate (BaTiO3) solid solution system, good piezoelectric properties together with high Curie temperatures were observed by introducing low temperature sintering followed by water-quenching process without any complicated grain alignment processing such as template grain growth method. With substitution of super-tetragonal components of bismuth zinc titanate [Bi(Zn0.5Ti0.5)O3] and bismuth gallium oxide (BiGaO3), piezoelectric properties were improved further. The observed piezoelectric sensor constant d33 is 402 pC/N with Curie temperature 449 oC. These piezoceramics showed temperature-stable piezoelectric properties and good long-term reliabilities.