Magnetic states in Fe-doped Bi_2Se_3 topological insulators nano-crystallites

摘要

The effect of Fe-doping on FexBi_(2-x)Se_3 (x = 0, 0.4, 1.0 and 1.4) nano-crystallites was experimentally investigated. X-ray diffraction (XRD) results showed that the structure of these samples had changed from amorphous structure for pure Bi_2Se_3 to polycrystalline structure with doping Fe_2O_3. Both SEM and TEM confirmed a combination of nanorods and nanospheres in soft accumulation of the samples with an average particle nano-size nearly 30 nm-33 run. Thermal analysis for all samples have been recorded and exhibited a weight loss at 500°C corresponds to the crystallisation of pure Bi_2Se_3. In addition, magnetic moment-field dependence confirmed an antiferromagnetic state in the composite. The magnetic moment and the saturation values were increased with increasing the Fe_2O_3 levels of doping. Experimental data confirmed that adding Fe-ions can creates a magnetic state in an insulator Bi_2Se_3 for applications of the next-generation of electronic devices including; spintronics, topological quantum computation and dissipation less topological electronics.