Effect of oxygen vacancies on intrinsic dielectric permittivity of strontium titanate ceramics

• HOSHINA Takuya

  Nano-Phononics Lab., School of Materials and Chemical Technology, Tokyo Institute of Technology

• SASE Ryuichi

  Nano-Phononics Lab., School of Materials and Chemical Technology, Tokyo Institute of Technology

• NISHIYAMA Junji

  Nano-Phononics Lab., School of Materials and Chemical Technology, Tokyo Institute of Technology

• TAKEDA Hiroaki

  Nano-Phononics Lab., School of Materials and Chemical Technology, Tokyo Institute of Technology

• TSURUMI Takaaki

  Nano-Phononics Lab., School of Materials and Chemical Technology, Tokyo Institute of Technology

Abstract

We prepared oxygen-deficient strontium titanate ceramics and measured the THz dielectric spectra to discuss the effect of oxygen vacancies on the intrinsic dielectric permittivity. In the presence of oxygen vacancies, the lattice volume of strontium titanate increased. First-principles calculation revealed that the expansion of the lattice originated from repulsion between the oxygen vacancies and cations, causing a decrease in the covalency of the Ti–O bonding. THz dielectric measurement using a far-infrared spectroscopic ellipsometer made it clear that the Slater-type phonon mode hardened and then the intrinsic permittivity of strontium titanate decreased in the presence of oxygen vacancies.

Journal

• Journal of the Ceramic Society of Japan

  Journal of the Ceramic Society of Japan 126 (5), 263-268, 2018-05-01

  The Ceramic Society of Japan

Keywords

• Strontium titanate
• Oxygen vacancy
• Dielectric property
• Ionic polarization
• THz response
• Ellipsometer
• First-principles calculation

Details

• CRID: 1390282680264160256
• NII Article ID: 130006730899
• DOI: 10.2109/jcersj2.17250
• ISSN: 13486535
• ISSN: 18820743
• Web Site: https://www.jstage.jst.go.jp/article/jcersj2/126/5/126_17250/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed