Physical properties of Ce3+xRu4Sn13−x single crystals

Single crystals of ${\mathrm{Ce}}_3+x{\mathrm{Ru}}₄{\mathrm{Sn}}_{13\ensuremath{-}x}$ $(0.05\ensuremath{\le}x\ensuremath{\le}0.34)$, which adopt the cubic structure ($Pm\overline{3}n$, No. 223), have been grown with Sn flux. Thermodynamic and transport property measurements from single-crystal samples do not show any sign of magnetic ordering down to 1.8 K and indicate coexistence of the Kondo effect and crystalline electric field effect. The local minimum in the electrical resistivity and highly enhanced specific heat values at low temperatures characterize this family as a heavy fermion Kondo lattice system. A broad peak is observed at $\ensuremath{\sim}$3.5 K for $x=0.05$ in the specific heat and magnetic susceptibility, suggesting a significant Kondo contribution, and the peak disappears as $x$ increases. The evolution of physical properties of ${\mathrm{Ce}}_3+x{\mathrm{Ru}}₄{\mathrm{Sn}}_{13\ensuremath{-}x}$ compounds can be attributed to the nature of the individual Ce ions that occupy two inequivalent $2a$ and $6d$ crystallographic sites.