Highly thermal-stable ferromagnetism by a natural composite.
Highly thermal-stable ferromagnetism by a natural composite.
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天然复合材料具有高度热稳定性铁磁性
DOI：
10.1038/ncomms13937
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发表时间：
2017-01-18
影响因子：
16.6
通讯作者：
Yan M
中科院分区：
文献类型：
--
作者：
Ma T;Gou J;Hu S;Liu X;Wu C;Ren S;Zhao H;Xiao A;Jiang C;Ren X;Yan M
随着温度的升高，所有铁磁材料的磁化强度和磁致伸缩等与磁有关的性能都会恶化，这是由于随着居里温度TC的接近，磁序逐渐丧失的结果。然而，从技术上讲，人们非常希望找到一种能够抵抗这种磁性退化并将磁性保持到TC以下的磁性材料，但这似乎与人们对铁磁性的传统看法背道而驰。在这里，我们发现Fe-Ga合金在880 K附近表现出高度的热稳定性磁化强度，并且在很宽的温度范围内磁致伸缩几乎没有恶化。这种反常行为源于该合金的双磁相性质，即在两个磁相之间发生逐渐的结构-磁性转变，从而通过具有较大磁化强度的铁磁相的生长来补偿磁劣化。我们的发现可能有助于开发高度热稳定性的铁磁和磁致伸缩材料。
All ferromagnetic materials show deterioration of magnetism-related properties such as magnetization and magnetostriction with increasing temperature, as the result of gradual loss of magnetic order with approaching Curie temperatureTC. However, technologically, it is highly desired to find a magnetic material that can resist such magnetism deterioration and maintain stable magnetism up to itsTC, but this seems against the conventional wisdom about ferromagnetism. Here we show that a Fe–Ga alloy exhibits highly thermal-stable magnetization up to the vicinity of itsTC, 880 K. Also, the magnetostriction shows nearly no deterioration over a very wide temperature range. Such unusual behaviour stems from dual-magnetic-phase nature of this alloy, in which a gradual structural-magnetic transformation occurs between two magnetic phases so that the magnetism deterioration is compensated by the growth of the ferromagnetic phase with larger magnetization. Our finding may help to develop highly thermal-stable ferromagnetic and magnetostrictive materials.