Enhancing Magnetic Ordering in Cr-Doped Bi2Se3 Using High-T-C Ferrimagnetic Insulator

TitleEnhancing Magnetic Ordering in Cr-Doped Bi2Se3 Using High-T-C Ferrimagnetic Insulator
Publication TypeJournal Article
Year of Publication2015
AuthorsLiu, W, He, L, Xu, Y, Murata, K, Onbasli, MC, Lang, M, Maltby, NJ, Li, S, Wang, X, Ross, CA, Bencok, P, van der Laan, G, Zhang, R, Wang, KL
JournalNano Letters
Volume15
Issue1
Pagination764 - 769
Date Published2015/01//
Abstract

We report a study of enhancing the magnetic ordering in a model magnetically doped topological insulator (TI), Bi2-xCrxSe3, via the proximity effect using a high-T-C ferrimagnetic insulator Y3Fe5O12. The FMI provides the TI with a source of exchange interaction yet without removing the nontrivial surface state. By performing the elemental specific X-ray magnetic circular dichroism (XMCD) measurements, we have unequivocally observed an enhanced T-C of 50 K in this magnetically doped TI/FMI heterostructure. We have also found a larger (6.6 nm at 30 K) but faster decreasing (by 80% from 30 to 50 K) penetration depth compared to that of diluted ferromagnetic semiconductors (DMSs), which could indicate a novel mechanism for the interaction between FMIs and the nontrivial TIs surface.