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Visualizing bulk band structure in Fe4N thin films by spin- and angle-resolved photoelectron spectroscopy

Karen Nakanishi1,*, Masaaki Kakoki1,*, Kiyotaka Ohwada1, Kenta Kuroda1,2,3, Kazuki Sumida4,5, Hitoshi Sato5, Koji Miyamoto5, Taichi Okuda2,3,5, Shinji Isogami6,† et al.

Keisuke Masuda6,‡, Yuya Sakuraba6, and Akio Kimura1,2,3,7,§

  • 1Physics Program, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
  • 2International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM2), 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8531, Japan
  • 3Research Institute for Semiconductor Engineering, 1-4-2 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan
  • 4Materials Sciences Research Center, Japan Atomic Energy Agency, Hyogo 679-5148, Japan
  • 5Research Institute for Synchrotron Radiation Science (HiSOR), Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima 739-0046, Japan
  • 6National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, Japan
  • 7Synchrotron Radiation Research Center, National Institutes for Quantum Science and Technology (QST), Sayo, Hyogo, Japan

  • *These authors contributed equally to this work.
  • †Contact author: isogami.shinji@nims.go.jp
  • ‡Contact author: masuda.keisuke@nims.go.jp
  • §Contact author: akiok@hiroshima-u.ac.jp
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Phys. Rev. Research 8, 023257 – Published 8 June, 2026

DOI: https://doi.org/10.1103/mlcy-gszb

Abstract

The bulk band structure of an in situ prepared ferromagnetic Fe4N thin film has been investigated using spin- and angle-resolved photoelectron spectroscopy with synchrotron radiation. It was observed that most of the bands near the Fermi level are of minority spin. The experimental results are well reproduced by first-principles calculations. Our orbital analysis of the band structure has revealed that the electron pocket near the Γ point is primarily attributed to the Fe 3dxy orbital of the Fe(II) site, while the electron pocket near the M point is associated with the Fe(II) 3dz2 orbital. Our observation of real band structure in Fe4N thin films could provide valuable insight into the properties of anisotropic magnetoresistance and anomalous Nernst effect.

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Phys. Rev. Research 8, 023257– Published 8 June, 2026
  • Received 18 May 2025
  • Accepted 3 May 2026
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