NaZn13型La(Fe,Si,Co) 13化合物の巨大な負の熱膨張
Rongjin Huang1, Yanying Liu, Wei Fan
1Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, China.
Journal of the American Chemical Society
|July 27, 2013
まとめ
La(Fe,Si) 13化合物は,工業用途に有用な負の熱膨張 (NTE) を表しています. 特にコバルトを含む組成を最適化すると,NTEの窓が広がり,室温での応用の可能性が向上する.
科学分野:
- 材料科学 材料科学とは
- 固体物理 固体物理学
背景:
- La(Fe,Si) 13ベースの化合物は,磁熱性物質として知られています.
- これらの材料は,キュリー温度近くにおいて,著しい負の熱膨張 (NTE) を表しています.
- 工業的なNTEアプリケーションにおけるそれらの可能性は十分に探求されていません.
研究 の 目的:
- NaZn13型LaFe13-xSixおよびLaFe11.5-xCoxSi1.5化合物の線形NTE特性を合成し,調査する.
- NTE特性を高めるための化学組成を最適化するために.
- これらの化合物が工業用途のNTE材料としての可能性を評価する.
主な方法:
- NaZn13型LaFe13-xSixおよびLaFe11.5-xCoxSi1.5化合物の合成について.
- 構成最適化による線形負の熱膨張 (NTE) 性質の調査.
- コバルト (Co) ドーピングレベルを調整することによって,NTE特性の調整.
主要な成果:
- 化学組成を最適化して,急激な体積変化を継続的な膨張に成功させた.
- コバルト (Co) の含有量の増加により,NTEはより高い温度にシフトし,運用ウィンドウを広げました.
- LaFe10.5Co1.0Si1.5化合物は,室温を含む110 Kの範囲 (240350 K) で,26.1 × 10(-6) K(-1) の線形NTE係数を示した.
結論:
- La (Fe,Si) 13ベースの化合物の制御された組成は,調節可能なNTE特性を可能にします.
- 大規模なNTEと広い運用ウィンドウは,潜在的な産業用途を示唆しています.
- これらの材料は,特に室温のアプリケーションでは,効果的なNTE材料として有望です.
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