$Ru_3Sn_7$: Phonon Reference for Superconducting $Mo_3Sb_7$

In order to search for phonon reference for dimer-gapped superconducting $Mo_3Sb_7$, measurements of specific heat $(C_p(T))$ and electrical resistivity (ρ(T)) of $Ru_3Sn_7$ were performed in the temperature range 2-300 K. The phonon part of $C_p(T)$ and ρ(T) of $Ru_3Sn_7$ can satisfactorily be explained describing the spectrum with one Einstein and two Debye modes. We found $Θp_{E}$ ≈ 100 K, $Θp_{D1}$ ≈ 185 K and $Θp_{D2}$ ≈298 K. The magnetic specific heat of $Mo_3Sb_7$ exhibits a sharp maximum at T*= 50 K, below which follows a gap function. Magnetic resistivity increases as -lnT with decreasing temperature and shows maximum at T*.