Phase Formation and Structural Sequence of Highly-Oriented MBE-Grown NiTiCu Shape Memory Thin Films
Phase Formation and Structural Sequence of Highly-Oriented MBE-Grown NiTiCu Shape Memory Thin Films
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高取向 MBE 生长 NiTiCu 形状记忆薄膜的相形成和结构序列
DOI：
10.2320/matertrans.43.933
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
M. Moske
中科院分区：
文献类型：
--
作者：
R. Hassdorf;J. Feydt;René Pascal;S. Thienhaus;M. Boese;Tobias Sterzl;B. Winzek;M. Moske
我们提出了一项研究，展示了可控的形状记忆薄膜生长的能力，使用分子束外延。在这里，NiTiCu合金薄膜生长，这是已知的表现出马氏体相变远高于室温。值得注意的是，这些薄膜的微观结构被发现是非常不同的，与传统的溅射多晶薄膜：在这里，微晶是高度定向在±3沿着膜平面法线。此外，马氏体取向的分裂被检测到，指示两组特定的马氏体变体的选择。机械应力测量揭示了高比率的可恢复应力，即使对于低于500纳米厚度的膜。这些结果开辟了可能性，专门修改的形状记忆薄膜的微观结构和晶体取向，从而提出有前途的特性，特别是在他们的超弹性行为。
We present a study demonstrating the capability for controlled shape memory thin film growth using molecular beam epitaxy. Here, NiTiCu alloy films were grown which are known to exhibit the martensitic transformation well above room temperature. Remarkably, the microstructure of these films was found to be very different compared to conventionally sputtered polycrystalline films: here, the crystallites are highly oriented within ±3 ◦ along the film plane normal. Moreover, a splitting of the martensite orientation is detected indicating the selection of two specific sets of martensite variants. Mechanical stress measurements reveal a high ratio of recoverable stress even for films below 500 nm thickness. These results open up the possibility to specifically modify the microstructure and crystallographic orientation of shape memory thin films and thus suggest promising characteristics, especially in regard to their superelastic behavior.