Tarasiuk I. Interaction of components in the Li-Cu-{Al,Sn} and Li-Ag-{In,Sn,Sb} systems: phase equilibria and crystal structure of compounds.

The isothermal sections of the Li-Cu-{Al,Sn}, Li-Ag-{Sn,Sb} (both at 200 °C) and Li-Ag-In (at room temperature) phase diagrams in the whole concentration range were constructed based on the results of X-ray phase and X-ray structure analyses for the first time. The existence of eight known and twelve new ternary compounds was found in the investigated systems from X-ray single-crystal and powder diffraction data, the crystal structures were determined for nine of them. The investigated compounds belong to 14 structure types (ST). Seven ST are new (solved and refined by single-crystal method): Li8Cu12+xAl6-x, Li12Cu16+xAl26-x, Li12Cu13Al14, Li408Cu144Al783, Li18Cu16Al7, Li12Cu14Al12 and Li278(Ag,In)154). Different crystallochemical relations of crystal structures of novel compounds to known structure types were analysed. The crystal structures of two new binary compounds Li3Ag and Li3In were determined. The temperature phase transition from the cubic (ST CsCl) to the tetragonal (ST UPb) modification was revealed for the phase LiAg at 95-200 °C. The limits of solid solutions based on Ag3In and Li3Sb binary compounds were determined and margin compositions of solid solution based on LiIn were refined. It was found, that these solid solutions are formed by partial atomic substitution.