Burn D M, Duffy L B, Fujita R, Zhang S L, Figueroa A I, Herrero-Martin J, van der Laan G, Hesjedal T
Magnetic Spectroscopy Group, Diamond Light Source, Didcot, OX11 0DE, United Kingdom.
Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom.
Sci Rep. 2019 Jul 25;9(1):10793. doi: 10.1038/s41598-019-47265-7.
Chromium telluride compounds are promising ferromagnets for proximity coupling to magnetic topological insulators (MTIs) of the Cr-doped (Bi,Sb)(Se,Te) class of materials as they share the same elements, thus simplifying thin film growth, as well as due to their compatible crystal structure. Recently, it has been demonstrated that high quality (001)-oriented CrTe thin films with perpendicular magnetic anisotropy can be grown on c-plane sapphire substrate. Here, we present a magnetic and soft x-ray absorption spectroscopy study of the chemical and magnetic properties of CrTe thin films. X-ray magnetic circular dichroism (XMCD) measured at the Cr L edges gives information about the local electronic and magnetic structure of the Cr ions. We further demonstrate the overgrowth of CrTe (001) thin films by high-quality Cr-doped SbTe films. The magnetic properties of the layers have been characterized and our results provide a starting point for refining the physical models of the complex magnetic ordering in CrTe thin films, and their integration into advanced MTI heterostructures for quantum device applications.
碲化铬化合物有望成为铁磁体，用于与Cr掺杂的（Bi，Sb）（Se，Te）类材料的磁性拓扑绝缘体（MTIs）进行近邻耦合，因为它们含有相同的元素，这简化了薄膜生长过程，同时也因其晶体结构兼容。最近，已经证明可以在c面蓝宝石衬底上生长具有垂直磁各向异性的高质量（001）取向CrTe薄膜。在此，我们展示了对CrTe薄膜的化学和磁性性质的磁性和软X射线吸收光谱研究。在Cr L边缘测量的X射线磁圆二色性（XMCD）给出了有关Cr离子局部电子和磁性结构的信息。我们进一步证明了高质量Cr掺杂SbTe薄膜在CrTe（001）薄膜上的过生长。对这些层的磁性进行了表征，我们的结果为完善CrTe薄膜中复杂磁有序的物理模型以及将其集成到用于量子器件应用的先进MTI异质结构中提供了一个起点。
