論文

査読有り
2023年5月

Control of conductivity in Fe-rich cobalt-ferrite thin films with perpendicular magnetic anisotropy

Physical Review Materials
  • Masaya Morishita
  • ,
  • Tomoyuki Ichikawa
  • ,
  • Masaaki A. Tanaka
  • ,
  • Motoharu Furuta
  • ,
  • Daisuke Mashimo
  • ,
  • Syuta Honda
  • ,
  • Jun Okabayashi
  • ,
  • Ko Mibu

7
5
記述言語
掲載種別
研究論文(学術雑誌)
DOI
10.1103/PhysRevMaterials.7.054402

We fabricated two types of cobalt-ferrite (001) thin films, insulative Fe-rich cobalt-ferrite CoxFe3-xO4+δ (I-CFO) and conductive Fe-rich cobalt-ferrite CoyFe3-yO4 (C-CFO), with perpendicular magnetic anisotropy (PMA) on MgO (001) substrates. Although the stoichiometric cobalt ferrite is known as an insulating material, it is found that the conductivity of Fe-rich cobalt ferrites can be controlled by changing the source materials and deposition conditions in the pulsed laser deposition technique. The I-CFO and C-CFO films exhibit PMA through the in-plane lattice distortion. We investigated the Fe-ion-specific valence states in both I-CFO and C-CFO films by Mössbauer spectroscopy and x-ray magnetic circular dichroism and found that the difference in conductivity corresponds to the abundance ratio of the Fe2+ state at the octahedral B-site (Oh) in the inverse spinel structure. Furthermore, first-principles calculations reproduce the changes in the density of states at the Fermi level depending on the cation vacancies at the B-site, which explains the difference in conductivity between I-CFO and C-CFO.

リンク情報
DOI
https://doi.org/10.1103/PhysRevMaterials.7.054402
Scopus
https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85159772088&origin=inward
Scopus Citedby
https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85159772088&origin=inward
ID情報
  • DOI : 10.1103/PhysRevMaterials.7.054402
  • eISSN : 2475-9953
  • ORCIDのPut Code : 135095550
  • SCOPUS ID : 85159772088

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