Verwey型チャージオーダリングとプレッシャー下でのFe4O5のサイト選択モット移行
Samar Layek1,2, Eran Greenberg3,4, Stella Chariton3
1School of Physics and Astronomy, Tel Aviv University, 69978 Tel Aviv, Israel.
Journal of the American Chemical Society
|June 1, 2022
まとめ
高圧は混合バルエンスFe4O5を 絶縁体から金属に変換し,電荷の配列と磁気モメントを崩壊させます この研究で,この複雑な酸化鉄の 圧力調節可能な電子と磁気状態が明らかになった.
科学分野:
- 凝縮物質物理学
- 材料科学
- 固体化学
背景:
- 電子相関によって導かれる金属分離器の移行は,凝縮された物質において根本的なものです.
- 混合バレンスの化合物はしばしば電荷順序 (CO) を示し,複雑な相につながります.
- マグネタイト (Fe3O4) は,議論の余地のある電荷の順序を持つ混合バレンスの材料の典型的な例である.
研究 の 目的:
- 高圧下での混合バレンスのFe4O5の電子的,磁的,構造的性質を調査する.
- Fe4O5における電荷の順序とその移行の性質を理解する.
- Fe4O5の振る舞いを他の電荷有序物質と統一する顕微鏡の説明を提供する.
主な方法:
- 高解像度のX線微分
- 電気抵抗の測定
- 密度関数理論と動的平均場理論 (DFT+DMFT) の計算.
主要な成果:
- 周囲の条件では,Fe4O5は,Verwey型の電荷順序を持つ狭間隔離体である.
- 圧力 (~100 GPaまで) の下では,Fe4O5は電子と磁気移行を示します.
- 場所選択的な断熱器から金属への移行は, ~84 GPa で発生し,その伴い,バレンスの変化とCOの崩壊が起こります.
結論:
- Fe4O5は"トリメロン"/"ディメロン"状態と競合する圧力誘発の電荷順序を表示する.
- この研究は,Fe4O5のCOメカニズムを磁石と稀土ニッケラートに統一しています.
- Fe4O5の包括的な圧力-温度相図が示されています.
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