Superconductivity in novel Ge-based skutterudites: {Sr,Ba}Pt_4Ge_{12}

Abstract

Combining experiments and ab initio models we report on $\mathrm{SrP}{\mathrm{t}}_4\mathrm{G}{\mathrm{e}}_{12}$ and $\mathrm{BaP}{\mathrm{t}}_4\mathrm{G}{\mathrm{e}}_{12}$ as members of a novel class of superconducting skutterudites, where Sr or Ba atoms stabilize a framework entirely formed by Ge-atoms. Below $T_c=5.35$ K, and 5.10 K for $\mathrm{BaP}{\mathrm{t}}_4\mathrm{G}{\mathrm{e}}_{12}$ and $\mathrm{SrP}{\mathrm{t}}_4\mathrm{G}{\mathrm{e}}_{12}$, 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.

4 pages, 4 figures, accepted for publication in PRL