Giant inverse magnetocaloric effect near room temperature in Co substituted NiMnSb Heusler alloys
Giant inverse magnetocaloric effect near room temperature in Co substituted NiMnSb Heusler alloys
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DOI：
10.1088/0022-3727/42/3/035009
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发表时间：
2009-02
期刊：
影响因子：
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通讯作者：
A. Nayak;K. Suresh;A. Nigam
中科院分区：
文献类型：
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作者：
A. Nayak;K. Suresh;A. Nigam
研究了Co对Ni50−xCoxMn38Sb12(x=0，2，3，4，5)Heusler合金的结构、磁和磁热效应的影响。用X射线衍射仪研究了马氏体相从奥氏体相的演化过程。马氏体相变温度随Co含量的增加而单调下降。在室温附近，Co替代后的平均磁化强度有显著的提高。在磁场为50kOe时，x=5时的最大磁熵变为34J kg−1K−1，室温附近的磁熵变为2 9J kg−1K−1。与逆马氏体相变相关的强磁-结构耦合的磁化强度的显著增加是导致这些化合物中巨大的MCE的原因。
The effect of Co on the structural, magnetic and magnetocaloric effect (MCE) of Ni50−xCoxMn38Sb12 (x = 0, 2, 3, 4, 5) Heusler alloys was studied. Using x-ray diffraction, we show the evolution of the martensitic phase from the austenite phase. The martensitic transition temperature is found to decrease monotonically with Co concentration. Remarkable enhancement of MCE is observed near room temperature upon Co substitution. The maximum magnetic entropy change of 34 J kg−1 K−1 was achieved for x = 5 at 262 K in a field of 50 kOe and a value of 29 J kg−1 K−1 was found near room temperature. The significant increase in the magnetization with large magneto-structural coupling associated with the reverse martensitic transition is responsible for the giant MCE in these compounds.