Abstract
Muon spin relaxation and rotation (mu SR) measurements have been performed to study the superconducting properties of Ca3Ir4Sn13. Zero-field mu SR data shows no sign of any magnetic anomaly in Ca3Ir4Sn13 at the superlattice transition temperature, T* or in the superconducting ground state. Transverse-field mu SR measurements in the vortex state provided the temperature dependence of the magnetic penetration depth lambda. The dependence of lambda(-2) with temperature is consistent with the existence of a single 8-wave energy gap in the superconducting state of Ca3Ir4Sn13 with a gap value of 1.51(5) meV at absolute zero temperature. The magnetic penetration depth at zero temperature lambda(0) is 351(4) nm. The ratio Delta(0)/k(B)T(c) = 2.41(8) indicates that Ca3Ir4Sn13 is a strong-coupling superconductor.