Temperature dependence of the giant magnetostrain in a NiMnGa magnetic shape memory alloy
Temperature dependence of the giant magnetostrain in a NiMnGa magnetic shape memory alloy
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DOI：
10.1063/1.1953927
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发表时间：
2005-06
影响因子：
4
通讯作者：
Chengbao Jiang;Jingmin Wang;Huibin Xu
中科院分区：
文献类型：
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作者：
Chengbao Jiang;Jingmin Wang;Huibin Xu
研究了具有五层马氏体（5M）结构的Ni50Mn27.5Ga22.5磁性形状记忆合金在110K至300K温度范围内磁致应变的温度依赖性。发现磁致应变的温度阈值为 166K。在该温度以上实现了 6.3% 的巨磁致应变，而在该温度以下则没有监测到磁致应变。在温度阈值附近未检测到马氏体相变。随着温度的降低，晶格参数a略有增加，c大幅减少，四方性（a∕c−1）急剧增加。四方性的增加被认为与磁致应变的温度阈值有关，通过诱导电子结构、孪晶结构或在温度阈值以下具有相同5M马氏体结构的变体类型的变化。该解释是合理理解的，因为只有少数具有相同 5M 马氏体结构的样品...
The temperature dependence of the magnetostrain was investigated in the Ni50Mn27.5Ga22.5 magnetic shape memory alloy with a five-layer martensitic (5M) structure in the temperature range from 110Kto300K. A temperature threshold at 166K was found for the magnetostrain. A giant magnetostrain of 6.3% was achieved above the temperature, while no magnetostrain was monitored below the temperature. No intermartensitic transformation was detected around the temperature threshold. The lattice parameter a slightly increases, c largely decreases, and the tetragonality (a∕c−1) drastically increases with decreasing the temperature. The increase of the tetragonality is thought to be related to the temperature threshold of the magnetostrain by inducing a change of the electronic structure, twin structure, or the type of the variant with the same 5M martensitic structure below the temperature threshold. The interpretation is reasonably understood by the fact that only few samples with the same 5M martensitic structure ex...