Crystal structure and low-temperature physical properties of R3M4Sn13(R=Ce,La;M=Ir,Co) intermetallics

We have synthesized single crystalline samples of R3M4Sn13 (R=Ce, La; M=Ir, Co) using a Sn-flux method. Measurements of magnetic susceptibility and heat capacity indicate heavy-fermion behavior for the Ce-based compounds. The crystal structure of these intermetallic compounds has been determined by Rietveld refinement from X-ray powder diffraction data. They crystallize in a Yb3M4Sn13 type structure (Pm-3n), which has 40 atoms per unit cell. The low-temperature physical properties of these intermetallic compounds are reported