Fig. 4

Emergence of superconductivity under high pressure and temperature–pressure phase diagram in FePSe₃. a The in-plane electrical resistivity of FePSe₃ single crystal as a function of temperature, and applied pressures 9.0, 10.8, 12.5, 17.1, 23.2, 25.5, and 29.6 GPa. b The in-plane electrical resistivity of FePSe₃ single crystal as a function of temperature, and applied pressures 29.6, 33.6, 38.0, and 41.4 GPa. Insets of a, b show the enlarged low-temperature parts of the measured resistivity. Line colors are the same as those used in a, b. Inset of b shows the photograph of a single-crystal FePSe₃ inside a DAC for resistivity measurements. The scale bar is 100 μm. c The temperature dependence of the electrical resistivity of FePSe₃ at 29.6 GPa under magnetic fields of 0, 0.1, 0.25, 0.5, 1, 2, and 5 T. Inset shows the field dependence of T_c for FePSe₃ at 29.6 GPa. d Temperature–pressure phase diagram of FePSe₃, where solid circles represent the pressure dependence of the onset superconducting transition temperatures (5*T_c), and the blue triangles represent the pressure dependence of Hall coefficient. T_N represents the Neel temperature of FePSe₃