Investigations of the TlInp2Se6–In4(P2Se6)3 System and its Optical Properties

The equilibrium phases were investigated and the corresponding phase diagram constructed for the TlInP2Se6–In4(P2Se6)3 system from physical and chemical analyses, namely differential thermal analysis (DTA), X-ray diffraction (XRD), and microstructural analysis (MSA). It was established that this system belongs to the eutectic type and is characterized by the formation of boundary solid phases containing complex compounds. Single crystals of the compounds TlInP2Se6 and In4(P2Se6)3 were grown using the Bridgman method. Both crystals were found to exhibit diffuse reflection spectra and photoinduced dependence of birefringence at various IR wavelengths generated by CO2 laser irradiation. Birefringence properties were investigated using the Senarmont method