Electrical Transport Properties of van der Waals Insulator CrGeTe₃ under Extremely High Pressure up to 52 GPa

The layered ternary chalcogenide CrGeTe3 has attracted considerable interest as a two-dimensional van der Waals magnet. The application of high pressures induces unique property modifications, such as a drastic increase in Curie temperature to a value close to room temperature. In this study, the electrical transport properties of CrGeTe3 were investigated under extremely high pressures up to 52 GPa to understand the physical properties of the high-pressure phase further, particularly the appearance of superconductivity. The temperature dependences of the resistance, Hall effect, and magnetoresistance of CrGeTe3 at high pressures were measured using an originally designed diamond anvil cell. The structural phase transition from (R) over bar3 to R3 and amorphization are investigated by in situ Raman spectroscopy and X-ray diffraction at high pressures. Unlike in CrSiTe3, the superconductivity in CrGeTe3 in the high-pressure phase does not emerge up to 52 GPa. Amorphization is the possible main reason for the absence of superconductivity in CrGeTe3.