Compounds with layered structures in the systems CuGa5S8/CuIn5S8 and AgGa5S8/AgIn5S8

The title systems have been investigated by single crystal and powder X-ray diffraction methods on quenched samples. In the system AgGaxIn5-xS8 spinel type phases are formed up to x < 2. A compound crystallising with a hexago nal layered structure is obtained for 2 < x less than or equal to 3. The cr ystal structure of this layered phase has been solved on a single crystal o f composition AgGa3In2S8: space group P6(3)mc, Z = 2, a = 380.80 and c = 30 76.4 pm. The structure is isotypic to the Zn2In2S5 (II a) type. The sample AgGa4InS8 crystallises in a Wurtzite like structure with a = 377.25 and c = 616.1 pm. In the system CuGaxIn5-xS8 a new compound with layered structure has been detected for 1 < x less than or equal to 2 which crystallises hex agonally with a = 350.28 and c = 3073.4 pm (x = 2). For the spinel CuIn5S8 an exchange of In by Ga is not detected.