2010年12月2日
Impact of amorphization on the magnetic properties of EuO-TiO2 system
Physical Review B - Condensed Matter and Materials Physics
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- 巻
- 82
- 号
- 22
- 開始ページ
- 224403
- 終了ページ
- 1
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1103/PhysRevB.82.224403
Recently, we have reported amorphization-induced ferromagnetism in a magnetic oxide
whereas crystalline EuTiO3 is an antiferromagnet, its amorphous counterpart shows a ferromagnetic transition. In this paper, we have investigated the magnetic properties of amorphous EuO-TiO2 system in detail. The present compounds, i.e., amorphous EuTiO3 and Eu 2 TiO4, exhibit a paramagnetic-ferromagnetic transition followed by a spin-glass transition upon cooling down, thereby being characterized as reentrant ferromagnets. Interestingly, the magnetic ordering temperatures of amorphous EuTiO3 and Eu2 TiO4 are comparable to and higher than those of their crystalline counterparts, respectively, indicating the enhancement of ferromagnetic interactions by amorphization. The origin of these features is discussed in terms of both the essential structural difference between amorphous and crystalline oxides and the magnetism unique to the crystalline EuO-TiO2 compounds. We also find a correlation between the magnitude of ferromagnetic interactions and the covalency of Eu-O bonds. © 2010 The American Physical Society.
whereas crystalline EuTiO3 is an antiferromagnet, its amorphous counterpart shows a ferromagnetic transition. In this paper, we have investigated the magnetic properties of amorphous EuO-TiO2 system in detail. The present compounds, i.e., amorphous EuTiO3 and Eu 2 TiO4, exhibit a paramagnetic-ferromagnetic transition followed by a spin-glass transition upon cooling down, thereby being characterized as reentrant ferromagnets. Interestingly, the magnetic ordering temperatures of amorphous EuTiO3 and Eu2 TiO4 are comparable to and higher than those of their crystalline counterparts, respectively, indicating the enhancement of ferromagnetic interactions by amorphization. The origin of these features is discussed in terms of both the essential structural difference between amorphous and crystalline oxides and the magnetism unique to the crystalline EuO-TiO2 compounds. We also find a correlation between the magnitude of ferromagnetic interactions and the covalency of Eu-O bonds. © 2010 The American Physical Society.
- ID情報
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- DOI : 10.1103/PhysRevB.82.224403
- ISSN : 1098-0121
- ISSN : 1550-235X
- SCOPUS ID : 78650870767