Crystal growth, transport, and magnetic properties of Ln3Co4Sn13 (Ln=La, Ce) with a perovskite-like structure

Ln₃Co₄Sn₁₃ (Ln=La, Ce) have been synthesized by flux growth and characterized by single crystal X-ray diffraction. These compounds adopt the Yb₃Rh₄Sn₁₃-type structure and crystallize in the cubic space group (No. 223) with Z=2. Lattice parameters at 298 K are , , and , for the La and Ce analogues, respectively. The crystal structure consists of an Sn-centered icosahedron at the origin of the unit cell, which shares faces with eight Co trigonal prisms and 12 Ln-centered cuboctahedra. Magnetization data at 0.1 T show paramagnetic behavior down to 1.8 K for Ce₃Co₄Sn₁₃, with per Ce³⁺, while conventional type II superconductivity appears below 2.85 K in the La compound. Electrical resistivity and specific heat data for the La compound show a corresponding sharp superconducting transition at T_c∼2.85 K. The entropy and resistivity data for Ce₃Co₄Sn₁₃ show the existence of the Kondo effect with a complicated semiconducting-like behavior in the resistivity data. In addition, a large enhanced specific heat coefficient at low T with a low magnetic transition temperature suggests a heavy-fermionic character for the Ce compound. Herein, the structure and physical properties of Ln₃Co₄Sn₁₃ (Ln=La, Ce) are discussed.