Large positive magnetoresistance with high Hall mobility and intercalation of Fe dopants in the quenched Bi2Te3 single crystals
Journal
Journal of Alloys and Compounds
Journal Volume
844
Date Issued
2020
Author(s)
Wang S.-H., Shen D., Yang T.-W., Chen I.-N., Wang C.-H., Wang L.-M.
Abstract
A study of Fe-ion intercalation in Bi2Te3 probed by the x-ray diffraction, magnetization, Hall measurement, and spectra of synchrotron x-ray photoemission spectroscopy is reported, in which a large positive magnetoresistance (MR) and a high carrier mobility for applications have been achieved and probed in the quenched FexBi2Te3 single crystals with x = 0.01 and 0.15. Large positive MR of ?470% with a Hall mobility of ?44000 cm2/Vs at 5 K and 6 T has been observed on a quenched Fe0.01Bi2Te3 sample with a quenching temperature Tq of 400 °C, where the electrical parameters can be tuned by Tq. Larger c-axis lattice constants and electron-dominant carriers in the quenched samples lead to the inference that the doped Fe atoms are mostly located at the intercalated van der Waals gap positions and exist as a metallic state of Fe0, which is confirmed by the synchrotron x-ray photoemission spectroscopy (XPS) spectra. Combining the x-ray diffraction, magnetization, and Hall-coefficient studies, here we pave a simple way for probing into the location of Fe dopants in Bi2Te3. In addition, novel magnetotransports of Fe-doped Bi2Te3 associated with the absence of ferromagnetism have been presented, and satisfy the scenario that the topological surface state persists without the loss of topological insulating characteristics of the linear band dispersion, and the large MR may originate from the surface magnetism, even in the presence of Fe impurities. This study also discusses the huge enhancement of Hall mobility arising from the surface Dirac electrons that are accompanied with a modified band structure in quenched Fe0.01Bi2Te3. ? 2020 Elsevier B.V.
Subjects
Crystal impurities; Hall mobility; Hole mobility; Iron; Iron metallography; Lattice constants; Lead metallography; Magnetization; Magnetoresistance; Photoelectron spectroscopy; Single crystals; Tellurium compounds; Topology; Van der Waals forces; X ray diffraction; Electrical parameter; Hall measurements; High carrier mobility; Ion intercalation; Positive magnetoresistance; Quenching temperatures; Surface magnetism; Synchrotron x rays; Bismuth compounds
Type
journal article