Uniaxial-stress tuned large magnetic-shape-memory effect in Ni-Co-Mn-Sb Heusler alloys
Uniaxial-stress tuned large magnetic-shape-memory effect in Ni-Co-Mn-Sb Heusler alloys
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DOI：
10.1063/1.4976212
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发表时间：
2017-02
影响因子：
4
通讯作者：
C. Mejia;R. Küchler;A. Nayak;C. Felser;M. Nicklas
中科院分区：
文献类型：
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作者：
C. Mejia;R. Küchler;A. Nayak;C. Felser;M. Nicklas
Heusler 形状记忆合金 Ni45Co5Mn38Sb12 和 Ni44Co6Mn38Sb12 的应变和磁化强度综合测量为强磁结构耦合提供了证据。在高温下的铁磁奥氏体相和较低温度下的弱磁性、低对称性马氏体相之间的马氏体相变过程中，样品长度变化高达 1%。在中等单轴应力下，样品长度的变化增加至约 3% 并饱和，表明单一马氏体变体的稳定性。施加磁场也可以引发反向马氏体转变：我们发现，在马氏体转变热滞后的温度范围内，施加磁场可以引发样品的亚稳态膨胀，而在稍低的温度下，场响应是可逆的。这些发现为未来在执行器和机械开关等领域使用 Ni(Co)-Mn-Sb 基 Heusler 化合物提供了关键信息。
Combined strain and magnetization measurements on the Heusler shape-memory alloys Ni45Co5Mn38Sb12 and Ni44Co6Mn38Sb12 give evidence for strong magneto-structural coupling. The sample length changes up to 1% at the martensitic transformation, between a ferromagnetic, austenitic phase at high temperatures and a weakly magnetic, low-symmetry martensitic phase at lower temperatures. Under moderate uniaxial stress, the change in the sample length increases to and saturates at about 3%, pointing to stabilization of a single martensitic variant. A reverse martensitic transformation can also be induced by applying magnetic field: we find that within the temperature range of thermal hysteresis of the martensitic transformation, applying a field can induce a metastable expansion of the sample, while at slightly lower temperatures, the field response is reversible. These findings provide key information for future use of Ni(Co)-Mn-Sb-based Heusler compounds in, e.g., actuators and mechanical switches.