Magnetocrystalline anisotropy of #-Fe2O3

Authors

• Imran Ahamed, Indian Institute of Technology
• Rohit Pathak, Indian Institute of Technology
• Ralph Skomski, University of Nebraska-LincolnFollow
• Arti Kashyap, Indian Institute of TechnologyFollow

ORCID IDs

Rohit Pathak

Document Type

Article

Date of this Version

2017

Citation

AIP ADVANCES 8, 055815 (2018)

Comments

© 2017 Author(s).

https://doi.org/10.1063/1.5007659

Abstract

The epsilon Fe₂O₃ phase of iron oxide has been studied to understand the spin structure and the magnetocrystalline anisotropy in the bulk and in thin films of ε-Fe₂O₃ and Co-doped ε-Fe₂O₃. The preferential magnetization direction in the nanoparticles of ε-Fe₂O₃ is along the a-axis [M. Gich et al., Chem. Mater. 18, 3889 (2006)]. Compared to the bulk band gap of 1.9 eV, the thin-film band gap is reduced to 1.3 eV in the Co-free films and to 0.7 eV in the film with partial Co substitution. The easy magnetization direction of the bulk and Co-free ε-Fe₂O₃ is along the a-axis, but it switches to the a-axis on Co substitution. All three systems exhibit in-plane anisotropies associated with the orthorhombic crystal structure of the oxide.