ホーム > 研究活動 > 口頭発表(2014) > First-Principles Study of Magnetic Properties of ε-Fe2O3

研究活動

First-Principles Study of Magnetic Properties of ε-Fe2O3

The European Conference, Physics of Magnetism (2014), Poznan, Poland

2014年6月23日(月)

Daisuke Hirai、Yoshihiro Gohda、Shinji Tsuneyuki ( Tokyo Univ. )

概要/Abstract

ε-Fe2O3 has been attracting strong attention as a novel magnetic material because of itslargest coercivity, HC=2T, among all of the oxides [1,2].
However, the origin of high coercivityremains unclear, which is crucial not only for scientific interests, but also for materials design.
Also, the magnetization is so small due to superexchange interactions via oxygen atoms: itsimprovement is an important key for technological applications.
In this study, we performed first-principles calculations on ε-Fe2O3, based on densityfunctional theory.
We show that the pristine ε-Fe2O3 exhibits zero magnetization, which is incontrast to the finite magnetizaion in experiments at low temperature [1].
The influence of asingle oxygen vacancy is also discussed, where it is introduced in the unit cell with 40 atoms.
Itis clarified that only the introduction to a specific oxygen site contributes to finitemagnetization, whose structure is the most stable among those having a single oxygenvacancy.
In the presention, we also talk about the magnetic crystalline anisotropy, which isalso strongly affected.

References

[1] S.-I.OhkoshiandH.Tokoro,Bull.Chem.Soc.Jpn. 86, 897(2013).
[2] M.Yoshikiyo,K.Yamada,A.Namai,andS.-I.Ohkoshi,J.Phys.Chem.C 116, 8688(2012).


研究活動

元素戦略拠点

触媒・電池元素戦略拠点
触媒・電池元素戦略研究拠点 (京都大学)
東工大元素戦略拠点
東工大元素戦略拠点 (東京工業大学)
構造材料元素戦略研究拠点
構造材料元素戦略研究拠点 (京都大学)
高効率モーター用磁性材料技術研究組合
高効率モーター用 磁性材料技術研究組合