Anomalous specific heat, magnetic, and electrical transport properties around magnetic instability in Ce3−xLaxCo4Sn13

Abstract

Ce3Co4Sn13 exhibits interesting physical properties including a large increase in the magnetic specific heat, ΔC(T)/T, at low-temperatures with a maximum value of about 4JK−2molCe−1 and a cross-over from heavy fermion behavior with antiferromagnetic correlations at low magnetic field to single impurity Kondo behavior by applying the field larger than ∼3 T. In order to study the expected quantum criticality of Ce3Co4Sn13 we investigated electrical resistivity, magnetoresistivity, magnetic susceptibility and specific heat of Ce3−xLaxCo4Sn13 and showed that partial substitution of Ce by La does not lead to long range magnetic order, and the low-temperature properties are not typical of the quantum critical point (QCP). The magnetoresistivity of Ce3−xLaxCo4Sn13 has a conventional Kondo character. With increasing of the magnetic field resistivity follows power-law behavior over one decade in temperature for the samples with x ≠ 0 of the series, and exponent n in ρ ∼ Tn is strongly field dependent. The low-temperature specific heat of Ce3−xLaxCo4Sn13 exhibits evolution from a magnetically correlated heavy fermion state to a single impurity state at the critical concentration x = xC = 0.6, however, for xC the C(T)/T behavior is not typical for QCP. The low-temperature resistivity and magnetic susceptibility data give evidence for changeover from Kondo lattice to a single-ion Kondo behaviour at xC, when the La content in Ce3−xLaxCo4Sn13 increases.