Magnetoelastic Coupling in Ni-Mn-Ga Magnetic Shape Memory Alloy
Magnetoelastic Coupling in Ni-Mn-Ga Magnetic Shape Memory Alloy
复制标题
Ni-Mn-Ga磁性形状记忆合金中的磁弹性耦合
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
O. Heczko
中科院分区：
文献类型：
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作者：
O. Heczko
磁弹性耦合在孪生变体的磁感应重新定向或重新分布（MIR）机制中的作用仍然存在一些争议。为了评估这种作用，测量了不同 Ni-Mn-Ga 单晶转变为 5M（表现出 MIR）和 NM（无 MIR）马氏体的普通磁致伸缩。 Ni-Mn-Ga奥氏体的磁致伸缩相对较低，并且在接近马氏体转变时急剧增加。这与弹性模量的软化有关。观察到的相反符号的高场贡献可能是由于高阶弹性常数对磁场的依赖性。马氏体的磁致伸缩很难确定，因为它被更强的中红外效应所掩盖，必须使用间接方法。结果在 MIR 磁致弹性模型框架下进行了讨论，并与磁能模型进行了比较。
The role of magnetoelastic coupling in the mechanism of magnetically induced reorientation or redistribution (MIR) of twin variants is still a matter of some controversy. To evaluate this role ordinary magnetostriction of different Ni-Mn-Ga single crystals transforming to 5M (exhibiting MIR) and NM (no MIR) martensite were measured. The magnetostriction of Ni-Mn-Ga austenite is relatively low and steeply increases when approaching to martensite transformation. This is correlated to the softening of elastic modulus. Observed high field contribution of opposite sign may be due to the dependence of higher order elastic constant on magnetic field. The magnetostriction of martensite is difficult to determine as it is masked by much stronger MIR effect and indirect method must be used. The results are discussed in the frame of magnetoelastic model for MIR and compared with magnetic energy model.