QUASI-ONE-DIMENSIONAL SUPERCONDUCTIVITY IN Sc5Ir4Si10 AND Lu5Ir4Si10 SINGLE CRYSTALS

Anisotropic superconducting properties in Sc 5 Ir 4 Si 10 and Lu 5 Ir 4 Si 10 single crystals are investigated. Both of these compounds are found to show quasi-one-dimensional superconductivity with better conduction along the c-axis and anisotropy parameter of about 2. Reflecting the partial destruction of the Fermi surface due to charge-density-wave formation, Lu 5 Ir 4 Si 10 shows higher residual resistivity, lower superconducting transition temperature, and longer magnetic penetration depths compared with those of Sc 5 Ir 4 Si 10. Similarity of superconducting properties including the anisotropy in Sc 5 Ir 4 Si 10 and Lu 5 Ir 4 Si 10 indicates that the absence of the charge-density wave in Sc 5 Ir 4 Si 10 is controlled by a subtle difference in the Fermi surface topologies in these two compounds.