Characterization of the Heavy Metal Pyrochlore Lattice Superconductor CaIr2

Abstract

We report the electronic properties of the cubic laves phase superconductor CaIr2(Tc = 5.8 K), in which the Ir atoms have a pyrochlore lattice. The estimated superconducting parameters obtained from magnetization and specific heat measurements indicate that CaIr2 is a weakly coupled BCS superconductor. Electronic band structure calculations show that the Ir d-states are dominant at the Fermi level, creating a complex Fermi surface that is impacted substantially by spin–orbit coupling.