Pressure-induced Superconductivity in CaLi2

A search for superconductivity has been carried out on the hexagonal polymorph of Laves-phase CaLi2, a compound for which Feng, Ashcroft, and Hoffmann predict highly anomalous behavior under pressure. No superconductivity is observed above 1.10 K at ambient pressure. However, high-pressure ac susceptibility and electrical resistivity studies to 81 GPa reveal bulk superconductivity in CaLi2 at temperatures as high as 13 K. The normal-state resistivity shows a dramatic increase with pressure.