We report the discovery of superconductivity in pressurized $\mathrm{CeRhG}{\mathrm{e}}_3$, a nonsuperconducting member of the isostructural family of noncentrosymmetric heavy-fermion compounds $\mathrm{Ce}T{X}_3(T=\mathrm{Co}$, Rh, Ir and $X=\mathrm{Si}$, Ge). Superconductivity appears in $\mathrm{CeRhG}{\mathrm{e}}_3$ at a pressure of 19.6 GPa and the transition temperature $T_C$ reaches a maximum value of 1.3 K at 21.5 GPa. This finding provides an opportunity to establish systematic correlations between superconductivity and material properties within this family. Though ambient-pressure unit-cell volumes and critical pressures for superconductivity vary substantially across the series, all family members reach a maximum $T_C^{max}$ at a common (±1.7%) critical cell volume $V_{\mathrm{crit}}$, and $T_C^{max}$ at $V_{\mathrm{crit}}$ increases with increasing spin-orbit coupling strength of the $d$ electrons. These correlations show that substantial Kondo and spin-orbit couplings favor superconductivity in this family, the latter reflecting the role of broken centrosymmetry.

• Received 19 August 2017
• Revised 5 February 2018

DOI:https://doi.org/10.1103/PhysRevB.97.064514