Origin of structural instability in TlInS2(1−x)Se2xsolid solutions

Abstract

The influence of the isovalent substitution of selenium for sulfur in the anion sublattice of mixed TlInS2(1−x)Se2x crystals has been studied by means of dielectric measurements. It is shown that transformations in the In4(SxSe1−x)10 structural unit must be taken into account considering the nature of possible phase transitions in TlInS2(1−x)Se2 solid solutions. Possible mechanisms of the phase transition including instabilities in the electronic subsystem of pure TlInSe2 crystals are discussed.