Superconductivity in Novel Ge-Based Skutterudites:{Sr,Ba}Pt4Ge12

Combining experiments and ab initio models we report on ${\mathrm{SrPt}}_4{\mathrm{Ge}}_{12}$ and ${\mathrm{BaPt}}_4{\mathrm{Ge}}_{12}$ as members of a novel class of superconducting skutterudites, where Sr or Ba atoms stabilize a framework entirely formed by Ge atoms. Below $T_c=5.35$ and 5.10 K for ${\mathrm{BaPt}}_4{\mathrm{Ge}}_{12}$ and ${\mathrm{SrPt}}_4{\mathrm{Ge}}_{12}$, respectively, electron-phonon coupled superconductivity emerges, ascribed to intrinsic features of the Pt-Ge framework, where Ge-$p$ states dominate the electronic structure at the Fermi energy.