ABSTRACT
We have grown single crystals of the MnIn2Se4-xSx and we characterized them by optical and magnetic measurements. The optical energy gap of these single crystals has an indirect energy gap of 1.6 eV at RT for x = 0.2. At slightly higher energies the fundamental edge is followed by a direct gap with an energy of 1.78 eV at RT.
The random distribution of the Mn atoms generates frustration, probably leading to ferromagnetic clusters antiferromagnetically coupled between them. At low temperature a spin-glass like state was established
