Anomalous superconductivity and pressure induced phase transitions in black phosphorus

Pressure induced superconductivity in black phosphorus was measured along three different paths in P-T diagram. High-Tc was observed when pressure was continuously increased at liquid helium temperature. Pressure induced phase transitions has been also studied. A mechanism of the phase transition is closely related to the anomalous superconductivity. The high-Tc superconductivity of black-P may be attributed to the existence of superconducting phase in metallic phase.