CeIr3: superconductivity in a phase based on tetragonally close packed clusters

Abstract

We present the crystallographic analysis, superconducting and spectroscopic characterization, and theoretical modeling of CeIr3. Lattice parameters a = 5.2945(1) Å and c = 26.219(1) Å are found for the R-3m symmetry crystal structure, which are close to the literature values. CeIr3 is a moderate type-II superconductor (κGL = 17, λe–p = 0.65) below 2.5 K. Ce ions exhibit a strongly intermediate valence character as evidenced by x-ray photoelectron spectroscopy. The normal state magnetic susceptibility is weakly temperature dependent and follows the inter-configuration fluctuation model with a singlet Ce−4 f0 ground state. Theoretical calculations support a non-magnetic ground state of the system and reveal that Ir−5d states are dominant at the Fermi level.