CaLi2 superconductor under the pressure of 100 GPa: the thermodynamic critical field and the specific heat

Abstract

In this paper the thermodynamic properties of the CaLi2 superconductor have been studied at a pressure of 100 GPa. The thermodynamic critical field (HC) and the specific heats for the superconducting and normal states (CS and CN) have been obtained. The calculations have been made within the framework of the Eliashberg approach for a wide range of the Coulomb pseudopotential: μ⋆∈〈0.1,0.3〉. It has been shown that the low-temperature critical field and the specific heat jump at TC strongly decrease if μ⋆ increases. The value of the dimensionless ratio RC ≡ (CS − CN)/CN at the critical temperature differs significantly from the value predicted by the Bardeen–Cooper–Schrieffer (BCS) model. In particular, the parameter RC decreases from 1.83 to 1.73 with the increase of the Coulomb pseudopotential value. In the paper, the interpolation formulas for the functions TC(μ⋆) and RC(μ⋆) have also been given.