Structural phase transition and potential superconductivity initiated by pressure-driven in 1-CrSe.

The exploration of the superconducting properties of antiferromagnetic parent compounds containing transition metals under pressure provides a unique idea for finding and designing superconducting materials with better performance. In this paper, the close relationship between the possible superconductivity and structure phase transition of the typical van der Waals layered material 1-CrSeinduced by pressure is studied by means of electrical transport and x-ray diffraction for the first time. We introduce the possibility of pressure-induced superconductivity at 20 GPa, with a criticalof approximately at 4 K. The superconductivity persists up to the highest measured pressure of 70 GPa, with a maximum∼ 5 K at 24 GPa. We observed a structure phase transition from-31 to2/space group in the range of 9.4-11.7 GPa. The results show that the structural phase transition leads to the metallization of 1-CrSeand the further pressure effect makes the superconductivity appear in the new structure. The material undergoes a transition from a two-dimensional layered structure to a three-dimensional structure under pressure. This is the first time that possible superconductivity has been observed in 1-CrSe.