Development of ferromagnetism in the doped topological insulator Bi2-xMnxTe3

作者：Hor Y S^*; Roushan P; Beidenkopf H; Seo J; Qu D; Checkelsky J G; Wray L A; Hsieh D; Xia Y; Xu S Y; Qian D; Hasan M Z; Ong N P; Yazdani A; Cava R J

来源：Physical Review B, 2010, 81(19): 195203.

DOI：10.1103/PhysRevB.81.195203

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 T(C similar to)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 at 15 K in ferromagnetic Mn-doped Bi2-xMnxTe3 and that the dispersion relations of the surface states are changed in a subtle fashion.

• 出版日期2010-5-15