Size effects in the martensitic transformation hysteresis in Ni–Mn–Sn Heusler alloy films
Size effects in the martensitic transformation hysteresis in Ni–Mn–Sn Heusler alloy films
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DOI：
10.1016/j.actamat.2019.09.001
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发表时间：
2019-11
期刊：
影响因子：
9.4
通讯作者：
Yijia Zhang;J. Billman;P. Shamberger
中科院分区：
文献类型：
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作者：
Yijia Zhang;J. Billman;P. Shamberger
要了解小特征长度尺度对相变的影响，需要进行微观观察，以确定可能影响相变进程的机制。在这里，我们报道了在电化学沉积的Ni-Mn-SnHeusler合金薄膜中，光学显微镜观察到的与厚度有关的滞后现象。这种方法允许分析厚度减小的薄膜中单个颗粒内的尺寸相关相变行为。磁滞与晶粒度无关，而是随膜厚的减小而呈幂函数关系增大。这一行为归因于微尺度合金薄膜中薄膜/衬底界面的内耗能量耗散。
Understanding the effect of small characteristic length scales on phase transformations requires microscopic observations to identify mechanisms which may influence the progression of the transformation. Here, we report thickness-dependent hysteresis in electrochemically deposited Ni–Mn–Sn Heusler alloy films, as observed by optical microscopy. This approach allows for analyzing size dependent phase transformation behavior within individual grains from films with decreasing thickness. Hysteresis is not correlated with grain size, but increases with decreasing film thickness following a power law relationship. This behavior is attributable to internal friction-induced energy dissipation at the film/substrate interface in microscale alloy films.