ユーロピウムの急激な値変化 Eu2Pt6Al15 約45K
Mathis Radzieowski1, Frank Stegemann1, Theresa Block1
1Institut für Anorganische und Analytische Chemie , Universität Münster , Corrensstraße 30 , D-48149 Münster , Germany.
Journal of the American Chemical Society
|June 22, 2018
まとめ
ユーロピウム・プラチナ・アルミニウム (Eu2Pt6Al15) は,磁気および熱容量異常によって確認された,約40KのEu2+からEu3+へのユニークなバレンスの移行を示している. この変化が電子構造と結晶の大きさに影響します
科学分野:
- 固体化学
- 材料科学
- マグネティズム
背景:
- 複雑な結晶構造を持つ金属間化合物の合成と特徴付けは,新しい電子と磁性特性の発見に不可欠です.
- ユーロピウム (Eu) ベースの化合物は,興味深いバレンスの変動現象で知られています.
研究 の 目的:
- Eu2Pt6Al15の結晶構造を合成して解明する.
- 物理的性質,特に磁気および熱的振る舞いを調査し,基礎となる電子移行を理解する.
主な方法:
- 構造的決定のためのアーク溶融合成と単結晶X線 difraktion.
- 磁気感受性,熱容量,電気抵抗性,および物理的性質の測定のためのEu Mössbauerスペクトル.
- 構造の変化を観察するために,温度依存の粉末X線 difraktion.
主要な成果:
- Eu2Pt6Al15は (3+1) Dの不均衡な構造で結晶する.
- 磁気感受性,熱容量,および電気抵抗性の異常は40〜45Kで観察されました.
- Eu2+からEu3+への第1次バレンスの移行の証拠は,Mössbauer光譜で確認された.
- 同構造化合物 Eu2Pt6Ga15は13.1Kで二価のEuと反鉄磁性を示す.
結論:
- Eu2Pt6Al15は,温度によるバレンスの移行を Eu2+ から Eu3+ に受け,その物理的性質に影響を与えます.
- 構造的および電子的変化は,バレンスの移行に関連しています.
- Eu2Pt6Ga15との比較は,磁気と電子の振る舞いを決定するpnictogen要素 (Al対Ga) の役割を強調しています.
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