Development of ferromagnetism in the doped topological insulator Bi2-xMnxTe3
Development of ferromagnetism in the doped topological insulator Bi2-xMnxTe3
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DOI：
10.1103/physrevb.81.195203
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发表时间：
2010-05-15
影响因子：
3.7
通讯作者：
Cava, R. J.
中科院分区：
文献类型：
--
作者：
Hor, Y. S.;Roushan, P.;Cava, R. J.
通过对一系列不同含锰量的Bi2Te3单晶的测量，研究了掺锰Bi2Te3的铁磁性发展过程。扫描隧道显微镜分析表明，Mn取代在Bi位上，形成Bi2-xMnxTe3型化合物，且Mn取代是随机分布的，而不是聚集的。Mn掺杂首先产生具有类似居里行为的局域磁矩，但在Bi1.96Mn0.04Te3和Bi1.91Mn0.09Te3组分中，观察到T(C类似)9-12K的二级铁磁转变，铁磁性相的易磁化轴垂直于Bi2Te3基面。热电功率和霍尔效应测量表明，掺锰的Bi2Te3晶体为p型。角度分辨光电子能谱测量表明，在15K时，铁磁掺杂的Bi2-xMnxTe3中也存在着原始Bi2Te3中存在的拓扑表面态，并且表面态的色散关系发生了微妙的变化。
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.