Defect chemistry in perovskite ferroelectrics—History, present status, and future prospects—

• NOGUCHI Yuji

  Division of Information and Energy, Faculty of Advanced Science and Technology, Kumamoto University

Abstract

Perovskite ferroelectrics such as BaTiO₃ and PbTiO₃ provide various functions arising from spontaneous polarization. Here, the history, present status, and future prospects of the defect chemistry for BaTiO₃ are described. Even for non-doped samples, unintentional impurities including Fe govern the defect chemistry and its related properties. By solving multiple nonlinear equations employing the thermodynamic data set reported, majority/minority defect-concentration diagrams are available not only in a high-temperature equilibrium state but also in a low-temperature quenched one. As an example, the defect diagrams of Ba(Ti,Ca)O₃ and Ba(Ti,Mn)O₃ are shown, and the roles of fixed valence (Ca) and variable-valence (Mn) acceptors are explained. I also introduce an example of the defect control in BaTiO₃ single crystals; an activation of visible-light photovoltaic effect, where two redox potentials derived from Fe²⁺ and Fe³⁺ act as scaffolds for generating electron–hole pairs.

Journal

• Journal of the Ceramic Society of Japan

  Journal of the Ceramic Society of Japan 129 (6), 271-285, 2021-06-01

  The Ceramic Society of Japan

Keywords

• BaTiO₃
• PbTiO₃
• Perovskite
• Ferroelectric
• Defect
• Acceptor
• Donor
• Photovoltaic
• Photocatalyst

Details

• CRID: 1390288215571338112
• NII Article ID: 130008046939
• DOI: 10.2109/jcersj2.21039
• ISSN: 13486535
• ISSN: 18820743
• Web Site: https://www.jstage.jst.go.jp/article/jcersj2/129/6/129_21039/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed