MATERIALS WITH LAYERED STRUCTURES-IV - COGA1.8V0.2S4 AND COGA1.8TI0.2S4 2 NEW COMPOUNDS WITH FEGA2S4 STRUCTURE

The systems CoGa2S4CoV2S4 and CoGa2S4CoTi2S4 were studied by x-ray diffraction methods on quenched powder samples. In both systems new quaternary compounds CoGa1.8V0.2S4 and CoGa1.8Ti0.2S4 crystallizing in the trigonal layered structure of FeGa2S4 type (a=364.5, c=1203.8 pm and a=364.3, c=1205.8 pm, respectively.) have been obtained. They are formed only at temperatures above 800 and 900 °C, respectively, but can be quenched without decomposition. The phase width of both compounds increases with increasing temperature. For the end member compounds no phase width could be detected. © 1990.