Study of superconducting phase in cubic anti-perovskite Cr3RhN

The paper characterizes the thermodynamic properties of the phonon-induced superconducting state in Cr3RhN compound. Due to the high value of the electron-phonon coupling constant (λ ∼ 1), the calculations have been conducted in the framework of the Eliashberg formalism. It has been shown that the critical temperature (TC) is relatively high and it changes in the range from 14.24 K to 21.55 K, for the values of the Coulomb pseudopotential (μ⋆) from 0.3 to 0.1. Due to the significant strong-coupling and the retardation effects, the values of the order parameter (Δ), the thermodynamic critical field (HC), and the specific heat of the superconducting state (CS), highly deviate from the values predicted by the BCS model. In particular, RΔ=2Δ(0)kBTC∈{4.06,3.94,3.86},RH=TCCN(TC)HC2(0)∈{0.147,0.156,0.158}, and RC=ΔC(TC)CN(TC)∈{2.13,1.89,1.82}, respectively for μ⋆ ∈ {0.1, 0.2, 0.3}. The BCS model predicts RΔBCS=3.53,RHBCS=0.168, and RCBCS=1.43.