The Electronic Structures of Fe in bulk Y₃Fe₅O₁₂ garnet and the Bilayer Thin Films

Yi-Ying Chin^1*, H.-J. Lin², P. Wang³, D. Wu³, A. Tanaka⁴, C. T. Chen², A. Chainani²

¹Physics, National Chung Cheng University, Chiayi, Taiwan
²National Synchrotron Radiation Research Center, Hsinchu, Taiwan
³National Laboratory of Solid State Microstructures, Department of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
⁴Quantum Matter, Hiroshima University, Higashi-Hiroshima, Japan

* Presenter:Yi-Ying Chin, email:yiyingchin@ccu.edu.tw

For Spintronics, robust and reproducible transport of not only charge but also spin is required. The presence of pure spin currents was detected, leading to new functionalities. Ferromagnetic insulators, such as Y₃Fe₅O₁₂ (YIG), are expected to play an important role in generating pure spin current. YIG has a Curie temperature much higher than room temperature and thus has been intensively investigated, especially Pt/YIG bilayers owing to the large spin-orbit coupling of Pt.
Recently, an unconventional Hall effect as well as perpendicular magnetic anisotropy was observed in Pt/YIG thin films, indicating the importance of the interfacial effect. Therefore, it is important to probe the difference between this bilayer thin film and the bulk YIG. To investigate the electronic structures of bulk YIG and Pt/YIG thin films, we have performed X-ray magnetic circular dichroism experiments. Combining with our theoretical simulations, our data show that the electronic structures of Fe in Pt/YIG are different from that in bulk YIG. Our results further indicate the presence of the induced moment at the O site involved in the long-range magnetic interactions.

Keywords: Y₃Fe₅O₁₂ garnet, X-ray magnetic circular dichroism, Induced moment