  We report the discovery of superconductivity in pressurized CeRhGe3, until
now the only remaining non-superconducting member of the isostructural family
of non-centrosymmetric heavy-fermion compounds CeTX3 (T = Co, Rh, Ir and X =
Si, Ge). Superconductivity appears in CeRhGe3 at a pressure of 19.6 GPa and the
transition temperature Tc reaches a maximum value of 1.3 K at 21.5 GPa. This
finding provides an opportunity to establish systematic correlations between
superconductivity and materials 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 Tcmax
at a common critical cell volume Vcrit, and Tcmax at Vcrit increases with
increasing spin-orbit coupling strength of the d-electrons. These correlations
show that substantial Kondo hybridization and spin-orbit coupling favor
superconductivity in this family, the latter reflecting the role of broken
centro-symmetry.
