Structural investigations in the system Ga0.5V2S4–Ga0.5V2Se4

Abstract The system Ga 0.5 V 2 S 4 –Ga 0.5 V 2 Se 4 has been investigated by powder X-ray diffraction methods. A complete series of mixed crystals with a spinel structure with 1:1 ordering on the tetrahedral sites (space group F43m ) is formed. The lattice parameters of the cubic cell of the mixed crystals are linearly dependent on the S:Se ratio. The structures of the two border and one intermediate compound have been solved by the Rietveld method. Fractional parameters and interatomic distances are given for the different compositions. In the structure, the vanadium atoms are shifted from their ideal position to form isolated tetrahedral clusters with relatively short vanadium–vanadium distances of 288–296 pm.