Complex Crystal Chemistry of Yb6(CuGa)50 and Yb6(CuGa)51 Grown at Different Synthetic Conditions

• Published in: Crystal growth & design 2018-10, Vol.18 (10), p.6091-6099
• Main Authors: Mishra, Vidyanshu, Oliynyk, Anton O, Subbarao, Udumula, Sarma, Saurav Ch, Mumbaraddi, Dundappa, Roy, Soumyabrata, Peter, Sebastian C
• Format: Article
• Language: English
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/acs.cgd.8b00958

Two new compounds in the Yb–Cu–Ga system were discovered. Yb6(CuGa)50 was obtained as single crystals grown from gallium metal flux, and Yb6(CuGa)51 was synthesized by high-frequency induction heating technique. Structure analysis reveals new structure type for Yb6(CuGa)50 (C2/m space group), while Yb6(CuGa)51 crystallizes in rhombohedral space group R3̅m adopting the Th2Zn17 structure type. Both structures could be derived from the simplest layered packing, through CaCu5-type structure, as a common parent. Physical properties of the Yb6(CuGa)51 sample obtained bulk quantity were explored. The magnetic susceptibility study of Yb6(CuGa)51 in the temperature range of 2–300 K suggests a valence fluctuation at lower temperatures. X-ray absorption near edge spectroscopy suggests that Yb exists in mixed-valent state in Yb6(CuGa)51. Electrical resistivity measurement reveals that Yb6(CuGa)51 is metallic in nature and shows Fermi-liquid behavior in the temperature range from 3.5 to 25 K.