A ferromagnetic topological half-metal candidate: Carbon-doped Bi2Se3

Abstract

The high quality CxBi2Se3-x single crystals have been prepared by melt-grown reaction. The transport characteristicsmeasurement showed that the doping leads to the presence of ferromagnetism and the high external magnetic field could induce the metal-insulation transition. The metal-insulation transition temperature (Tm) is 169 K and 253 K for 6 T and 9 T, respectively. Analyze the curves of ρxy-B, we used the two-band model to fit MR and Hall coefficient of samples. The results indicated that electron-hole compensation may not be the only reason for the existence of unsaturated magnetoresistance in the material. To further, first principles are used to calculate the band structure of CxBi2Se3-x single crystals, and the feature of the topological half-metals has been suggested. According to the above results, we infer that CxBi2Se3-x single crystals may be candidate materials for topological half-metals.