Partially gapped Fermi surfaces in La3Co4Sn13revealed by nuclear magnetic resonance

Abstract

We report a study of a single-crystal La${}_{3}$Co${}_{4}$Sn${}_{13}$ by means of the specific heat and ${}^{59}$Co nuclear magnetic resonance (NMR) spectroscopy. A first-order phase transition with a marked peak at ${T}^{*}\ensuremath{\simeq}152$ K has been discerned by the specific heat measurement. The observed transition has been connected to a structural change from a simple cubic to a body-centered-cubic superstructure with crystallographic cell doubling, accompanied by the Fermi surface reconstruction. Indeed, NMR observations clearly indicate a significant change in the local electronic characteristics across this phase transition. The spin-lattice-relaxation rate measurement further provides an estimate of Co 3$d$ Fermi-level density of states ${N}_{d}$(${E}_{F}$), revealing a visible reduction in ${N}_{d}$(${E}_{F}$) in the low-temperature phase. This finding essentially associated with the partially gapped Fermi surfaces would be appropriate for the isostructural analog of Sr${}_{3}$Ir${}_{4}$ Sn${}_{13}$, which has been claimed to possess charge-density-wave (CDW) behavior with a three-dimensional crystallographic structure.