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arXiv · 1001.4834

The development of ferromagnetism in the doped topological insulator Bi2-xMnxTe3

Y. S. Hor·P. Roushan·H. Beidenkopf·J. Seo·D. Qu·J. G. Checkelsky·L. A. Wray·Y. Xia·S. -Y. Xu·D. Qian·M. Z. Hasan·N. P. Ong·A. Yazdani·R. J. Cava
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Abstract

The development of ferromagnetism in Mn-doped Bi2Te3 is characterized through measurements on a series of single crystals with different Mn content. Scanning tunneling microscopy analysis shows that the Mn substitutes on the Bi sites, forming compounds of the type Bi2-xMnxTe3, and that the Mn substitutions are randomly distributed, not clustered. Mn doping first gives rise to local magnetic moments with Curie-like behavior, but by the compositions Bi1.96Mn0.04Te3 and Bi1.91Mn0.09Te3 a second order ferromagnetic transition is observed, with Tc ~ 9-12 K. The easy axis of magnetization in the ferromagnetic phase is perpendicular to the Bi2Te3 basal plane. Thermoelectric power and Hall effect measurements show that the Mn-doped Bi2Te3 crystals are p-type. Angle resolved photoemission spectroscopy measurements show that the topological surface states that are present in pristine Bi2Te3 are also present in ferromagnetic Mn-doped Bi2-xMnxTe3, and that the dispersion relations of the surface states are changed in a subtle fashion.

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Y. S. Hor, P. Roushan, H. Beidenkopf, J. Seo, D. Qu, J. G. Checkelsky, L. A. Wray, Y. Xia, S. -Y. Xu, D. Qian, M. Z. Hasan, N. P. Ong, A. Yazdani, R. J. Cava. 2010-01-27. The development of ferromagnetism in the doped topological insulator Bi2-xMnxTe3. https://doi.org/10.1103/physrevb.81.195203

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