Superconductivity in a low carrier density system: A single crystal study of cubic Y3Ru4Ge13

We have successfully grown the single crystal of a low carrier density system Y3Ru4Ge13 which crystallises in the cubic crystal structure with the space group Pm3n. Y3Ru4Ge13 exhibits superconductivity below 2.85 K as determined from the electrical resistivity, magnetic susceptibility and heat capacity measurements. The bulk measurements indicate multi-band superconductivity in this low carrier system. Hall effect measurements show that the Hall coefficient RH is positive and it decreases rapidly with temperature which is highly unusual. The simple estimation of the carrier concentration gives a value (1020/cm3) which is 2-3 orders of magnitude lower than that of a conventional metal like Cu which seems to suggest that Y3Ru4Ge13 is a semimetal that display multiband superconductivity.