Discovery of a Superconducting Cu–Bi Intermetallic Compound by High‐Pressure Synthesis

A new intermetallic compound, the first to be structurally identified in the Cu?Bi binary system, is reported. This compound is accessed by high‐pressure reaction of the elements. Its detailed characterization, physical property measurements, and ab initio calculations are described. The commensurate crystal structure of Cu₁₁Bi₇ is a unique variation of the NiAs structure type. Temperature‐dependent electrical resistivity and heat capacity measurements reveal a bulk superconducting transition at T_c=1.36 K. Density functional theory calculations further demonstrate that Cu₁₁Bi₇ can be stabilized (relative to decomposition into the elements) at high pressure and temperature. These results highlight the ability of high‐pressure syntheses to allow for inroads into heretofore‐undiscovered intermetallic systems for which no thermodynamically stable binaries are known.