Magnetotransport properties of Bi100−xSbx topological insulator thin films

E. OSMIC; J. BARZOLA-QUIQUIA; W. BÖLMANN; P. G. BERCOFF; L. VENOSTA; P. HÄUSSLER

Conferencia; IEEE Around-the-Clock Around-the-Globe (AtC-AtG) Magnetics Conference 2022; 2022

The temperature dependence of the resistance R(T), and themagnetoresistance MR of Bi80Sb20, Bi85Sb15 and Bi90Sb10 topological insulator(TI) policrystalline thin films were measured. Samples were prepared bysequential flash-evaporation at room temperature and annealing at T=350 K. TheR(T) of the three investigated samples show metallic-like behavior attemperatures below 75 K, while at higher temperatures, R(T) curves show asemiconducting-like behavior. The MR of all samples is positive with a smalltemperature dependence. The highest MR (B=7 T) was observed in Bi85Sb15 with a ≈600 % and ≈125 % change at 5 K and 300K, respectively. Shubnikov de Haas oscillations are detected in the MR curve ofsample Bi85Sb15 up to ~21 K, these originate at the Fermi surface which has a2D character. This is a clear evidence of a 2D metallic state in TI materials[1,2]. References[1] A. Taskin,Y. Ando, “Quantum oscillations in atopological insulator Bi 1− x Sbx”, Physical Review B, 80(8), 2009, https://doi.org/10.1103/PhysRevB.80.085303[2] E. Osmic, J. Barzola-Quiquia, W. Böhlmann et al.,“Thermopower and magnetotransport properties of Bi100− xSbx topologicalinsulator thin films prepared by flash evaporation”, Journal of Physics andChemistry of Solids, 167, 110734, 2022.https://doi.org/10.1016/j.jpcs.2022.110734