Influence of Mn concentration on magnetic topological insulator Mn_xBi_2−xTe₃ thin-film Hall-effect sensor

Journal Article · Thu Jun 11 00:00:00 EDT 2015 · IEEE Transactions on Magnetics

DOI: https://doi.org/10.1109/TMAG.2015.2444378 · OSTI ID:1234460

Ni, Y. ^[1]; Zhang, Z. ^[1]; Nlebedim, I. C. ^[2]; Hadimani, R. L. ^[1]; Jiles, D. C. ^[1]

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1. Iowa State Univ., Ames, IA (United States)
2. Iowa State Univ., Ames, IA (United States); Ames Lab. (AMES), Ames, IA (United States)

Hall-effect (HE) sensors based on high-quality Mn-doped Bi₂Te₃ topological insulator (TI) thin films have been systematically studied in this paper. Improvement of Hall sensitivity is found after doping the magnetic element Mn into Bi₂Te₃. The sensors with low Mn concentrations, Mn_xBi_2-xTe₃, x = 0.01 and 0.08 show the linear behavior of Hall resistance with sensitivity about 5 Ω/T. And their Hall sensitivity shows weak dependence on temperature. For sensors with high Mn concentration (x = 0.23), the Hall resistance with respect to magnetic field shows a hysteretic behavior. Moreover, its sensitivity shows almost eight times as high as that of the HE sensors with low Mn concentration. The highest sensitivity can reach 43 Ω/T at very low magnetic field. This increase of Hall sensitivity is caused by the occurrence of anomalous HE (AHE) after ferromagnetic phase transition. Our work indicates that the magnetic-element-doped TIs with AHE are good candidates for HE sensors.

• Research Organization: Ames Lab. (AMES), Ames, IA (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-07CH11358
• OSTI ID: 1234460
• Report Number(s): IS-J--8870
• Journal Information: IEEE Transactions on Magnetics, Journal Name: IEEE Transactions on Magnetics Journal Issue: 11 Vol. 51; ISSN 0018-9464
• Publisher: Institute of Electrical and Electronics Engineers. Magnetics GroupCopyright Statement
• Country of Publication: United States
• Language: English