Evidence for ferromagnetic coupling at the doped topological insulator/ferrimagnetic insulator interface

One of the major obstacles of the magnetic topological insulators (TIs) impeding their practical use is the low Curie temperature (T[subscript c] ). Very recently, we have demonstrated the enhancement of the magnetic ordering in Cr-doped Bi₂Se₃ by means of proximity to the high-T[subscript c] ferri...

Olles dieđut

Bibliográfalaš dieđut
Váldodahkkit: Liu, Wenqing, He, Liang, Zhou, Yan, Murata, Koichi, Jiang, Ying, Wang, Yong, Xu, Yongbing, Zhang, Rong, Wang, Kang. L., Onbasli, Mehmet C., Ross, Caroline A
Eará dahkkit: Massachusetts Institute of Technology. Department of Materials Science and Engineering
Materiálatiipa: Artihkal
Almmustuhtton: American Institute of Physics (AIP) 2017
Liŋkkat:http://hdl.handle.net/1721.1/111957
https://orcid.org/0000-0003-2262-1249
Govvádus
Čoahkkáigeassu:One of the major obstacles of the magnetic topological insulators (TIs) impeding their practical use is the low Curie temperature (T[subscript c] ). Very recently, we have demonstrated the enhancement of the magnetic ordering in Cr-doped Bi₂Se₃ by means of proximity to the high-T[subscript c] ferrimagnetic insulator (FMI) Y₃Fe₅O₁₂ and found a large and rapidly decreasing penetration depth of the proximity effect, suggestive of a different carrier propagation process near the TI surface. Here we further present a study of the interfacial magnetic interaction of this TI/FMI heterostrucutre. The synchrotron-based X-ray magnetic circular dichroism (XMCD) technique was used to probe the nature of the exchange coupling of the Bi[subscript 2-x] Cr [subscript x] Se₃/Y₃Fe₅O₁₂ interface. We found that the Bi[subscript 2-x] Cr [subscript x] Se₃ grown on Y₃Fe₅O₁₂ (111) predominately contains Cr ³⁺ cations, and the spin direction of the Cr³⁺ is aligned parallel to that of tetrahedral Fe³⁺ of the YIG, revealing a ferromagnetic exchange coupling between the Bi [subscript 2-x] Cr [subscript x] Se₃ and the Y₃Fe₅O₁₂.