Title :
Influence of Mn Concentration on Magnetic Topological Insulator MnxBi2−xTe3 Thin-Film Hall-Effect Sensor
Author :
Ni, Y. ; Zhang, Z. ; Nlebedim, I.C. ; Hadimani, R.L. ; Jiles, D.C.
Author_Institution :
Dept. of Electr. & Comput. Eng., Iowa State Univ., Ames, IA, USA
Abstract :
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, MnxBi2-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.
Keywords :
Hall effect devices; bismuth compounds; doping profiles; magnetic hysteresis; magnetic transitions; manganese compounds; semiconductor materials; thin film sensors; topological insulators; Hall resistance; Hall sensitivity; Mn concentration influence; MnxBi2-xTe3; doping; ferromagnetic phase transition; magnetic element; magnetic topological insulator; magnetic-element-doped TI; thin-film Hall-effect sensor; Hall effect; Manganese; Resistance; Sensitivity; Temperature sensors; Topological insulators; X-ray diffraction; Hall effect devices; Hall-effect (HE) devices; sensitivity; thin films; topological insulators; topological insulators (TIs);
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2015.2444378
