Superconducting gap structure of the skutterudite LaPt4Ge12 probed by specific heat and thermal transport

We investigated the superconducting order parameter of the filled skutterudite LaPt4Ge12, with a transition temperature of Tc = 8.3 K. To this end, we performed temperature and magnetic-field dependent specific-heat and thermal-conductivity measurements. All data are compatible with a single superconducting s-wave gap. However, a multiband scenario cannot be ruled out. The results are discussed in the context of previous studies on the substitution series Pr1-xLaxPt4Ge12. They suggest compatible order parameters for the two end compounds LaPt4Ge12 and PrPt4Ge12. This is not consistent with a single s-wave gap in LaPt4Ge12 considering previous reports of unconventional and/or multiband superconductivity in PrPt4Ge12.