Superconductivity in the New Platinum Germanides MPt4Ge12 (M = Rare-earth and Alkaline-earth Metals) with Filled Skutterudite Structure

TL;DR

This paper reports the discovery of superconductivity in new platinum germanides with filled skutterudite structures, highlighting their structural, electronic, and magnetic properties, and identifying superconducting transition temperatures around 8.3K.

Contribution

It introduces new platinum germanide compounds with filled skutterudite structures and characterizes their superconducting properties for the first time.

Findings

Superconductivity observed in LaPt4Ge12 and PrPt4Ge12 below 8.3K.

Strong coupling and crystal electric field effects in PrPt4Ge12.

Similar but lower T_c behavior in SrPt4Ge12 and BaPt4Ge12.

Abstract

New germanium-platinum compounds with the filled-skutterudite crystal structure were synthesized. The structure and composition were investigated by X-ray diffraction and microprobe analysis. Magnetic susceptibility, specific heat, and electrical resistivity measurements evidence superconductivity in LaPt4Ge12 and PrPt4Ge12 below 8.3K. The parameters of the normal and superconducting states were established. Strong coupling and a crystal electric field singlet groundstate is found for the Pr compound. Electronic structure calculations show a large density of states at the Fermi level. Similar behavior with lower T_c was observed for SrPt4Ge12 and BaPt4Ge12.