RESUMO
Topological semimetal (TSM) AuTe2Br thin flakes have been studied by Raman spectroscopy and magneto-transport measurement. The angle-resolved polarized Raman spectrum of AuTe2Br (bulk and thin flake) shows strong anisotropy. Together with high resolution transmission electron microscopy (TEM), we establish a non-destructive method to determine the crystallographic orientation of AuTe2Br flakes. At high temperature (T > 50 K), the magneto-resistance (MR) of AuTe2Br thin flakes shows typical parabolic-like behavior, which can be well fitted by the two-fluid model. However, at low temperature (T ⩽ 30 K), the MR of thin flakes (<17 nm) clearly deviates from the two-fluid model as well as from the Kohler's rule, suggesting a new type of scattering emerging below 30 K. Several possible scattering mechanisms are discussed and the respective corrections to MR are compared with our experimental data. In addition, the conductivity of these metallic crystals is also found to be highly anisotropic, with the hole mobility along the a axis about five times higher than that along the c axis.
