La0.67-xBixSr0.33MnO3 (x=0.05-0.25) マンガニットにおける室温に合わせた磁気移行と磁熱特性
Parvathy Namboothiri1,2, K K Supin1,2, B Arun2
1Polymers and Functional Materials Department, CSIR-Indian Institute of Chemical Technology, Hyderabad-500007, India. mvas@iict.res.in.
Physical chemistry chemical physics : PCCP
|August 29, 2025
まとめ
ランタン・ストロンチウム・マンガニットにおけるビスムスの置換はキュリー温度を下げ,磁熱特性に影響を与え,室温に近い磁気冷却の応用の可能性を示している.
科学分野:
- 材料科学
- 固体物理学
- マグネティズム
背景:
- ランタン・ストロンチウム・マンガナイトは,有望な磁熱性特性で知られています.
- これらの特性を調整することは,磁気冷却技術の最適化に不可欠です.
研究 の 目的:
- La0.67Sr0.33MnO3の構造,磁気,および磁熱特性に対するビスマス (Bi) ドーピングの影響を調査する.
- 室温の磁気冷却のためのBi-dopedマンガニットの可能性を調査する.
主な方法:
- La0.67-xBixSr0.33MnO3 (x = 0.050.25) の固体合成について
- 構造分析のためのX線微分法 (XRD).
- 形状学のためのスキャニング電子顕微鏡 (SEM).
- 酸化状態のためのX線光電子スペクトロスコーピー (XPS).
- 磁気特性および磁熱効果 (MCE) の決定のための振動サンプル磁気測定 (VSM).
主要な成果:
- Biドーピングは,ロンボエドールと四角形の相が共存する混合相構造をもたらし,四角形の相分数はBi含有量とともに増加した.
- XPSは,Bi含有量の増加とともに,Mn3+/Mn4+の比率が低下していることを確認した.
- キューリー温度 (Curie temperature) は,グリッドの歪みと弱まった鉄磁気相互作用によるBi置換の増加とともに減少した.
- マグネトカロリック特性は体系的に研究され,Bi濃度に関連する傾向を示した.
結論:
- ビスムスの置換は,La0.67Sr0.33MnO3の構造的,磁性,および磁熱特性に大きな影響を与える.
- 観察された変化は,Bi-doped マンガナイトが特定の磁気冷却用途に合わせられる可能性があることを示唆しています.
- 効率的な室温磁気冷却のためにこれらの材料を最適化するためにさらなる研究が必要です.
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