Magnetotransport properties of square-net compounds of NbSiSb and NbGeSb single crystals

We successfully grew single crystals of Si- and Ge-square-net compounds of NbSiSb and NbGeSb whose excellent crystalline quality are verified using single-crystal x-ray diffraction theta-2 theta scans, rocking curves, scanning and transmission electron microscopies. Since these two compounds share major crystallographic similarity with the topological nodal-line semimetals of ZrSiS family, we employ density functional theory (DFT) calculations and magnetotransport measurements to demonstrate their band structures as well as the electron scattering mechanisms. DFT calculations show that the fermiology displays strong anisotropy from the crystallographicc-axis to theab-plane and weak anisotropy within theabplane, which is consistent with the strong anisotropic magnetotransport behaviors. Following the Kohler's scaling rule we prove that similar interband and intraband electron-phonon scattering mechanisms work in both the NbSiSb and NbGeSb compounds. The study of electronic transport mechanism in the presence of external magnetic field renders deep insight into topological behavior together with its Fermi surface, and the high similarity of crystallography and strong difference in band structures between the present single crystals and that of ZrSiS family provides the possibility to tune the band structure via element doping.