| Heusler合金Ni-Mn-Ga和NaZn13型化合物La（Fe,Co,M）13,M=Si,Al的巨大磁熵变（英） |
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| 作者姓名： | 胡凤霞 沈保根 |
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| 作者单位： | 中国科学院物理研究所凝聚态物理中心国家磁学重点实验室, 北京 100080 |
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| 基金项目： | supportedbytheStateKeyProjectofFundamentalResearch,theNationalNaturalScienceFoundationofChinaandtheBeijingNaturalScienceFoundationofChina. |
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| 摘 要： | 在Heusler合金Ni Mn Ga和NaZn13型化合物La(Fe,Co,M)13,M =Si,Al中很宽温度区间发现巨大磁熵变△S。这两种材料在室温区的磁熵变△S均显著地超过单质稀土Gd并达到著名的磁热效应材料Gd5Si2Ge2 合金的磁熵变幅度.Heusler合金Ni Mn Ga中的巨大磁熵变来源于具有一级相变特征的马氏结构相变。NaZn13型化合物La(Fe,Co,M)13,M =Si,Al中异常巨大的磁熵变与合金中的强的磁晶耦合相关,表现为居里温度附近晶格的巨大负膨胀。材料的低价格和其巨大磁熵变表明,Heusler合金Ni Mn Ga和NaZn1 3型化合物La(Fe,Co,M)13,M =Si,Al在很宽的高温区,尤其在室温区作为磁制冷工质非常有吸引力。
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| 关 键 词： | 磁熵变 磁制冷 Heusler合金NiMnGa NaZn13型化合物 |
| 收稿时间： | 2002-01-23 |
Great Magnetic Entropy Change in Heusler Alloys Ni-Mn-Ga and NaZn13-Type Compounds La(Fe,Co,M)13, M=Si,Al |
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| Authors: | HU Feng-Xia SHEN Bao-Gen |
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| Institution: | State Key Laboratory of Magnetism,Institute of Physics & Center of Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080 |
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| Abstract: | Very large magnetic entropy change △S in a wide temperature range was discovered in Heusler alloys Ni-Mn-Ga and NaZn13-type compounds La(Fe,Co,M)13, M=Si, Al. In room temperature range, the achieved △S in both materials significantly exceeds that of Gd and reaches that of Gd5Si2Ge2, which is well known for its giant magnetocaloric effect. The great △S in Heusler alloys Ni-Mn-Ga originates from the first-order martensitic-austensitic structural transition and the giant △S in La(Fe,Co,M13, M=Si, Al is associated with a strong structural and magnetic interplay, characterized by a drastic lattice contraction at Curie temperature T C. The superiority of low cost and giant magnetic entropy change suggests that both Heusler alloys Ni-Mn-Ga and NaZn13-type compounds La(Fe,Co,M13, M=Si, Al are promising candidates for magnetic refrigerants in an extended high temperature range, especially at room temperature. |
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| Keywords: | magnetic entropy change magnetic refrigerant Husler alloys Ni-Mn-Ga NaZn 13-type compounds |
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