Pressure-induced superconductivity in a shandite compound Pd3Pb2Se2with the Kagome lattice

Abstract

High pressure electric transport and synchrotron x-ray diffraction (XRD) measurements together with the first-principles calculations are performed on a shandite compound Pd3Pb2Se2 which contains the Kagome lattice of the transition metal Pd. A pressure-induced superconducting transition is observed above 25 GPa, for the first time in the shandite compounds, although the crystal structure of the compound seems to be very robust and persists up to the highest pressure in the XRD study (76.3 GPa). The superconducting transition temperature is about 2.2 K and almost does not change with pressure. The carrier density suddenly increases around 20 GPa possibly due to the emergence of two electron pockets at the Γ point. Our work indicates that the superconductivity in Pd3Pb2Se2 is strongly correlated to its electronic structure.