We report detailed Seebeck coefficient, Hall resistivity as well as specific heat measurement on Ca3Ir4Sn13 single crystals. The Seebeck coefficient exhibits a peak corresponding to the anomaly in resistivity at T∗, and the carrier density is suppressed significantly below T∗. This indicates a significant Fermi surface reconstruction and the opening of the charge density wave gap at the supperlattice transition. The magnetic field induced enhancement of the residual specific heat coefficient γ(H) exhibits a nearly linear dependence on magnetic field, indicating a nodeless gap. In the temperature range close to Tc the Seebeck coefficient can be described well by the diffusion model. The zero-temperature extrapolated thermoelectric power is very small, implying large normalized Fermi temperature. Consequently the ratio TFTc is very small. Our results indicate that Ca3Ir4Sn13 is a weakly correlated nodeless superconductor.
@article{arxiv.1604.08948,
title = {Ca$_3$Ir$_4$Sn$_{13}$: A weakly correlated nodeless superconductor},
author = {Kefeng Wang and C. Petrovic},
journal= {arXiv preprint arXiv:1604.08948},
year = {2016}
}