La2Co2Se2O3:珍しいコバルトスピン状態と可能な軌道順序を持つ準二次元モット断熱器
Cao Wang1, Ming-qiu Tan, Chun-mu Feng
1Department of Physics, Zhejiang University, Hangzhou 310027, People's Republic of China.
Journal of the American Chemical Society
|April 30, 2010
まとめ
新種のオキシセレニドであるLa(2)Co(2)Se(2)O(3) は,断熱的行動と220K近くの反鉄磁気移行を示しています.圧力は抵抗性を大幅に低下させ,結合スピンと軌道動態を明らかにします.
科学分野:
- 固体化学 固体化学
- マテリアルサイエンス 材料科学
- マグネティズム (磁気) とは
背景:
- オキシセレニドは,機能材料の新興クラスである.
- コバルトベースの化合物は,しばしば興味深い磁気および電子特性を示します.
研究 の 目的:
- 新しいコバルトオキシセレニドを合成し,特徴づけます.
- 周囲の環境や高圧条件下での磁気および電子特性を調査する.
主な方法:
- 真空下での固体反応合成.
- クリスタル構造の決定のためのX線 difraktion.
- 磁気感受性の測定. 磁気感受性の測定. 磁気感受性の測定. 磁気感受性の測定.
- 高圧下での抵抗性測定. 高圧下での抵抗性測定.
- LSDA+U バンド構造の計算.
主要な成果:
- I4/mmmで結晶化したLa(2)Co(2)Se(2)O(3) を成功して合成しました.
- 観測された反鉄磁気移行は約220Kで,磁気エントロピーは低スピンのCo2+) 状態を示唆しています.
- 材料は絶縁性 (抵抗力10^7オーム/cm) であるが,7GPaの圧力下では導電性となる.
- バンド構造の計算は,絶縁状態と低スピンを確認し,強力な軌道偏分と結合されたスピン-軌道ダイナミクスを示しています.
結論:
- La ((2) Co ((2) Se ((2) O ((3)) は,抗鉄磁性オキシセレニドの新型隔離剤である.
- 圧力によって引き起こされる金属性は,その電子性質の調節性を強調します.
- 旋回と軌道上の自由度間の相互作用は,その行動に極めて重要です.
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