A low-temperature Kerr effect microscope for the simultaneous magneto-optic and magneto-transport study of magnetic topological insulators
A low-temperature Kerr effect microscope for the simultaneous magneto-optic and magneto-transport study of magnetic topological insulators
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DOI：
10.1088/1361-6501/ab39b4
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发表时间：
2019-08
影响因子：
2.4
通讯作者：
Jieyi Liu;Angadjit Singh;J. Llandro;L. Duffy;Michael R Stanton;S. Holmes;M. Applegate;R. Phillips;T. Hesjedal;C. Barnes
中科院分区：
文献类型：
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作者：
Jieyi Liu;Angadjit Singh;J. Llandro;L. Duffy;Michael R Stanton;S. Holmes;M. Applegate;R. Phillips;T. Hesjedal;C. Barnes
磁光克尔效应（MOKE）显微镜涉及在微米级的横向分辨率磁化的表面敏感探测。在这里，我们提出了一种低温，聚焦极性MOKE显微镜，用于同时进行磁光和磁输运测量，其温度范围为1.6-300 K，并配备了能够提供高达9 T的磁场的磁体。在这种显微镜中，所有的光学元件都集成在一个独立的探头中，可以直接集成到许多非光学低温恒温器系统中。对图案化铁磁[CoFeB/Pt]n薄膜的二维磁化扫描表明磁化灵敏度为10 µrad（克尔角），空间分辨率为2.2 µm。光学和电学测量的组合提供了互补的温度相关信息，如通过对具有面外磁各向异性的磁性拓扑绝缘体薄膜的研究所证明的。使用这种互补的方法，我们研究了Cr和V共掺杂的Sb 2 Te 3薄膜中的第二相的影响，该薄膜在70 K以上显示出弱反局域化和各向异性磁阻效应的组合。我们的研究结果突出了MOKE和电输运的优点，以优化奇异的拓扑磁性材料，为节能的自旋电子器件铺平了道路。
Magneto-optic Kerr effect (MOKE) microscopy involves the surface-sensitive probing of magnetisation at micron-sized lateral resolution. Here, we present a low-temperature, focused polar MOKE microscope for simultaneous magneto-optic and magneto-transport measurements which has a temperature range of 1.6–300 K and is equipped with a magnet capable of delivering a field of up to 9 T. In this microscope, all optical components are integrated in a free-standing probe, allowing for straightforward incorporation into many non-optical cryostat systems. Two-dimensional magnetisation scans on patterned ferromagnetic [CoFeB/Pt]n films demonstrate a magnetisation sensitivity of 10 µrad (Kerr angle) and a spatial resolution of 2.2 µm. The combination of optical and electrical measurements provides complementary temperature-dependent information, as demonstrated by the study of magnetic topological insulator thin films with out-of-plane magnetic anisotropy. Using this complementary approach, we study the effects of a secondary phase in Cr and V co-doped Sb2Te3 thin films, which show a combination of weak antilocalisation and anisotropic magnetoresistance effects above 70 K. Our results highlight the virtue of MOKE and electrical transport to optimise exotic topological magnetic materials, paving the way for energy-efficient spintronic devices.