Coexisting ferromagnetic component and negative magnetoresistance at low temperature in single crystals of the VdW material GaGeTe

We report magnetoresistance and magnetization studies of single-crystal GaGeTe, which has been proposed as a Van der Waals material. Semi-metallic character is observed in the temperature (T) variation of resistivity (rho), following rho(T) & PROP; T2 at low temperature with a slope compatible with the usual spin-fluctuating system. Magne-toresistance (MR) at 2 K is negative and strongly dependent on the direction of the magnetic field (H) with respect to the crystallographic c-axis. MR changes sign with increasing temperature above -100 K, when H is applied along the c-axis. Hall measurements indicate the p-type conductivity with a considerable hole concentration of -8.7 x 10(19) cm(-3). Angle-resolved photoemission spectroscopy reproduces the reported results and confirms a peculiar dispersion shape of the hole-like band at the bulk high-symmetry T point near the Fermi energy indi-cating band inversion. Magnetic hysteresis measurement at 2 K shows diamagnetic behaviour at high-H, whereas a ferromagnetic (FM)-like magnetic hysteresis loop is observed at low-H in between +/- 4 kOe. The FM component disappears close to 3 K. Signature of spin-fluctuation in rho(T), negative MR, and low-T FM component without 3d or 4f impurities in GaGeTe is attractive for the fundamental interest.

Automated summary

The study reports magnetoresistance and magnetization properties of single-crystal GaGeTe, demonstrating its unique electrical and magnetic characteristics. Hall measurements indicate p-type conductivity, while angle-resolved photoemission spectroscopy confirms the peculiar dispersion shape of the valence band.