Evolution from a magnetically correlated state to a single impurity state in heavy fermion system Ce3−xLaxCo4Sn13

Abstract

AbstractCe3Co4Sn13 crystallizes in the cubic Yb3Rh4Sn13 structure, which is closely related to the one of scutterudites, well known thermoelectric materials. Ce3Co4Sn13 exhibits novel physical properties, a large increase in Cmag/T was recently observed at low temperatures with a maximum value of about 4 J K−2 ${\rm mol}_{{\rm Ce}}^{- 1} $. The specific heat data suggested that Ce3Co4Sn13 is likely near a magnetic quantum critical point (QCP). In this report we investigate the low‐temperature specific heat of Ce3−xLaxCo4Sn13 in order to study the proximity of Ce3Co4Sn13 to the possible magnetic QCP. We found the critical concentration xc ≈ 0.6 which separates the magnetically correlated state with a maximum in C(T)/T at ∼0.7 K for x < xc, and a single impurity state for x > xc in heavy fermion (HF) system Ce3−xLaxCo4Sn13. However, for xc the low‐temperature C(T)/T behaviour is not characteristic of the QCP.