Room-temperature skyrmions in strain-engineered FeGe thin films
Room-temperature skyrmions in strain-engineered FeGe thin films
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DOI：
10.1103/physrevb.101.220405
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发表时间：
2020-06-08
影响因子：
3.7
通讯作者：
Hauser, Adam J.
中科院分区：
文献类型：
--
作者：
Budhathoki, Sujan;Sapkota, Arjun;Hauser, Adam J.
斯格明子在低能耗和稳定的高密度信息存储方面具有广阔的前景，并且在实际应用中非常需要在室温或高于室温的情况下稳定斯格明子晶格（SkX）相。拓扑霍尔效应可用于识别高于室温的候选系统，这是洛伦兹电子显微镜直接观察的一个具有挑战性的机制。原子有序的 FeGe 薄膜在具有类似 4% 拉伸应变的 Ge(111) 衬底上外延生长。磁特性表明，由于应变，居里温度提高到 350 K，远高于 278 K 的体积值。在 10 到 330 K 之间观察到强烈的拓扑霍尔效应，在 330 K 处观察到强度显着增加。强度的增加发生在居里温度以下，类似于体料 FeGe 中 SkX 相的开始。结果表明，当施加显着的拉伸应变时，应变 FeGe 薄膜在高于室温时可能会出现 SkX 相。
Skyrmions hold great promise for low-energy consumption and stable high-density information storage, and stabilization of the skyrmion lattice (SkX) phase at or above room temperature is greatly desired for practical use. The topological Hall effect can be used to identify candidate systems above room temperature, a challenging regime for direct observation by Lorentz electron microscopy. Atomically ordered FeGe thin films are grown epitaxially on Ge(111) substrates with similar to 4% tensile strain. Magnetic characterization reveals enhancement of the Curie temperature to 350 K due to strain, well above the bulk value of 278 K. A strong topological Hall effect was observed between 10 and 330 K, with a significant increase in magnitude observed at 330 K. The increase in magnitude occurs just below the Curie temperature, similar to the onset of the SkX phase in bulk FeGe. The results suggest that strained FeGe films may host a SkX phase above room temperature when significant tensile strain is applied.