  Sub-Kelvin scanning tunnelling spectroscopy in the Chevrel Phases SnMo6S8 and
PbMo6S8 reveals two distinct superconducting gaps with Delta_1 = 3 meV, Delta_2
~ 1.0 meV and Delta_1 = 3.1 meV, Delta_2 ~ 1.4 meV respectively. The gap
distribution is strongly anisotropic, with Delta_2 predominantly seen when
scanning across unit-cell steps on the (001) sample surface. The spectra are
well-fitted by an anisotropic two-band BCS s-wave gap function. Our
spectroscopic data are confirmed by electronic heat capacity measurements which
also provide evidence for a twin-gap scenario.
