Superconductivity in Y3Ru4Ge13 and Lu3Os4Ge13: A comparative study

Abstract

A variety of unconventional superconductors have low carrier density as a common factor. However, The underlying mechanism of superconductivity in such low carrier density systems is not well understood. Besides, small carrier density is an unfavourable component for conventional superconductivity as described by The Bardeen-Cooper-Schrieffer (BCS) theory. Therefore, studying low carrier density systems can lead to a better understanding in such systems. In this paper, we report superconductivity property studies in low carrier density systems, Y3Ru4Ge13 and Lu3Os4Ge13, using various experimental techniques. Single crystals of Y3Ru4Ge13 and Lu3Os4Ge13 have been grown using The Czochralski crystal pulling method in a tetra-arc furnace. The x-ray diffraction experiment reveals that both compounds crystallize in cubic structure (space group Pm3n, no. 223). The transport, magnetization and heat capacity measurements show that Y3Ru4Ge13 single crystal undergoes a superconducting transition at 2.85 K, whereas, Lu3Os4Ge13 becomes superconductor at 3.1 K.