Electronic structure of CaFe2O4 with antiferromagnetic spin ordering

Kenji OBATA; Yuki OBUKURO; Shigenori MATSUSHIMA; Hiroyuki NAKAMURA; Masao ARAI; Kenkichiro KOBAYASHI

doi:10.2109/jcersj2.121.766

Feature: Advanced Bio-Ceramics Science and Technology for Life Innovation: Papers

Electronic structure of CaFe₂O₄ with antiferromagnetic spin ordering

Kenji OBATA, Yuki OBUKURO, Shigenori MATSUSHIMA, Hiroyuki NAKAMURA, Masao ARAI, Kenkichiro KOBAYASHI

Author information

Kenji OBATA
Department of Materials Science and Chemical Engineering, Kitakyushu National College of Technology (KCT)
Department of Biological Functions and Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology (KIT), Kitakyushu Science and Research Park
Yuki OBUKURO
Department of Biological Functions and Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology (KIT), Kitakyushu Science and Research Park
Shigenori MATSUSHIMA
Department of Materials Science and Chemical Engineering, Kitakyushu National College of Technology (KCT)
Department of Biological Functions and Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology (KIT), Kitakyushu Science and Research Park
Hiroyuki NAKAMURA
Integrated Arts and Science, Kitakyushu National College of Technology
Masao ARAI
Computational Materials Science Unit (CMSU), National Institute of Materials Science (NIMS)
Kenkichiro KOBAYASHI
Department of Materials Science and Chemical Engineering, Graduate School of Engineering, Shizuoka University

Keywords: Antiferromagnetic CaFe₂O₄, Ab initio calculation, FLAPW, GGA+U, Spin ordering

JOURNAL FREE ACCESS

2013 Volume 121 Issue 1417 Pages 766-769

DOI https://doi.org/10.2109/jcersj2.121.766

Details

Abstract

The electronic structure of antiferromagnetic CaFe₂O₄ is calculated by using a generalized gradient approximation considering on-site Coulomb interaction between d-electrons (GGA+U). We found that the antiferromagnetic phase is the most stable among non-magnetic, ferromagnetic, and antiferromagnetic phases. With GGA+U, the band gap energy of CaFe₂O₄ is calculated to be ca. 1.9 eV. The lower conduction band consists of the Fe 3d states split into t_2g and e_g states by the octahedral FeO₆ environment. The Ca 3d states distribute upper conduction bands. On the other hand, the valence band is mainly composed of the interaction between Fe 3d and O 2p states. The valence band maximum is approximately located at the Z-point and the conduction band minimum at the X-point. This means that antiferromagnetic CaFe₂O₄ is an indirect energy gap material. The absolute value of the magnetic moment at Fe sites is calculated to be 4.16 µ_B, which is very close to experimental values.

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