EuMn2P2における磁気相変化の結合と抑制
Tanya Berry1,2,3, Nicodemos Varnava4, Dominic H Ryan5
1Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States.
Journal of the American Chemical Society
|February 15, 2023
まとめ
EuMn2P2におけるマンガンの磁気順序を抑制し,それをクロスオーバーに変換する. 断熱器であるにもかかわらず,短距離の磁気相関関係が持続し,電子特性に影響を与えます.
科学分野:
- 凝縮物質物理学
- 材料科学
- 固体化学
背景:
- 固体内の電子は,競合する共振性,移位性,パウリ排除原理により複雑な結合を示す.
- EuMn2X2 (X = Sb, As, P) のような層状の材料は,多様な電子および磁気行動を表しています.
研究 の 目的:
- EuMn2P2における磁気配列に対する化学圧力の影響を研究する.
- 磁気順序,電子構造,隔離特性との関係を理解する.
主な方法:
- 合成されたEuMn2P2は,EuMn2X2ファミリーのエンドメンバーです.
- 温度依存特異熱と31P NMR測定を行った.
- 密度関数理論 (DFT) の計算を行った.
主要な成果:
- 化学的圧力によるマンガン (Mn) 磁気オーダーから磁気相クロスオーバーへの移行が観察されました.
- EuMn2P2は,約17Kで独特のユーロピウム (Eu) 反鉄磁性を持つ絶縁剤である.
- 短距離のMn磁気相関は,250〜100Kの間に検出され,共価結合形成が先行した.
- DFTの計算は,絶縁状態を維持するために反鉄磁気 Mnの配列の必要性を明らかにした.
結論:
- 化学的圧力は,EuMn2P2の長距離磁気順序を抑制するが,短距離の反鉄磁気相関を保持する.
- これらの持続的な相関は,電子帯の構造に影響を与え,材料の絶縁性を維持します.
- この発見は,磁気,電子構造,層状の材料の結合の 複雑な相互作用についての洞察を与えてくれます
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