Abstract Interfacing topological insulators (TI) with ferromagnetic (FM) layers is a promising route towards the next generation of ultra-low power spintronic devices based on charge-to-spin current conversion. Here, we present the Fe/Sb2Te3 interface structure, its chemical composition and magnetic properties. Thin films (30 nm) of the topological insulator Sb2Te3 were synthesized by Metal Organic Chemical Vapor Deposition (MOCVD) at room temperature on Si/SiO2 substrates, then capped with a 54Fe(10 nm)/57Fe(1 nm) bilayer by Pulsed Laser Deposition (PLD) to allow interface-sensitive Conversion Electron Mossbauer Spectroscopy (CEMS). X-ray diffraction (XRD) showed the polycrystalline nature of both the Fe and Sb2Te3 layers. X-ray reflectivity (XRR) identified a non-trivial layered structure with the presence of an intermixed layer at the Fe/Sb2Te3 interface. Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) confirmed the partial elemental interdiffusion between the Fe and Sb2Te3 layers. Interface-sensitive CEMS evidenced that about a half of the 1-nm-thick 57Fe layer in contact with Sb2Te3 coordinates ferromagnetically, whereas the remaining paramagnetic fraction preferentially bonds with Te. The Fe/Sb2Te3 system was shown to have a far from sharp interface, exhibiting a marked chemical reactivity already at room temperature. The tendency of Fe to preferentially bond with the chalcogenide element of topological insulators has been previously observed for the interface with Bi2Se3 and Bi2Te3, thus suggesting a possible universal behavior at the interface between Fe and chalcogenide-based TI.

中文翻译：

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Fe/Sb2Te3 界面的化学、结构和磁性能

摘要 拓扑绝缘体 (TI) 与铁磁 (FM) 层的接口是基于电荷到自旋电流转换的下一代超低功率自旋电子器件的有前途的途径。在这里，我们介绍了 Fe/Sb2Te3 界面结构、其化学成分和磁性。拓扑绝缘体 Sb2Te3 的薄膜 (30 nm) 在室温下通过金属有机化学气相沉积 (MOCVD) 在 Si/SiO2 衬底上合成，然后通过脉冲激光用 54Fe(10 nm)/57Fe(1 nm) 双层覆盖沉积 (PLD) 以允许界面敏感转换电子穆斯堡尔光谱 (CEMS)。X 射线衍射 (XRD) 显示了 Fe 和 Sb2Te3 层的多晶性质。X 射线反射率 (XRR) 确定了非平凡的层状结构，在 Fe/Sb2Te3 界面存在混合层。飞行时间二次离子质谱 (ToF-SIMS) 证实了 Fe 和 Sb2Te3 层之间的部分元素相互扩散。界面敏感 CEMS 证明，与 Sb2Te3 接触的 1nm 厚 57Fe 层的大约一半以铁磁性方式配位，而剩余的顺磁性部分优先与 Te 结合。Fe/Sb2Te3 系统被证明具有远非尖锐的界面，在室温下已经表现出明显的化学反应性。先前已经在与 Bi2Se3 和 Bi2Te3 的界面中观察到 Fe 优先与拓扑绝缘体的硫族元素结合的趋势，