Synthesis and physical properties of the system (GeS2)(80-x)(Ga2S3)(20):xPr glasses

High purity (GeS2)(80-x)(Ga2S3)(20). xPrCl(3)(x=1,2,3), (GeS2)(79)(Ga2S3)(20)Pr6O11 glasses were prepared and their basic thermal and optical properties were determined. The glass transition temperature T-g is in the region 399-404 degrees C. The glass-forming criteria (Delta T is an element of(123-128 degrees C), H-r is an element of(0.59-0.66), S is an element of(2.37-3.29) are changed by Pr doping only a little. The short-wavelength absorption edge lies near 2.7 eV, the doping by Pr creates new absorption bands which can be assigned to the H-3(4)-H-3(6), H-3(4)-F-3(3), H-3(4)-3F(4), H-3(4)-P-3(0) and H-3(4)-P-3(1) electron transitions. The experimentally found oscillator strengths calculated from absorption spectra lies between those of Pr doped halide and chalcohalide glasses. The long-wavelength absorption edge was found near 800-1000 cm(-1) and it corresponds to multiphonon Ge-S and Ga-S vibrations. The far-IR diffuse reflectance spectra were measured and the spectrum revealed by Kubelka-Munk method. The spectrum was deconvoluted into several bands which can be assigned to GeS4 and GaS4 tetrahedra vibrations. The narrow luminescence bands corresponding to electron transitions in Pr3+ ions(20000, 17857, 15873, 15220, 14326, 13947 and 13459 cm-') with the most intensive band near 15220 cm(-1) were found. These bands can be assigned to the transitions from the P-3(0) and D-1(2) levels to F-3(4), F-3(3), F-3(2), H-3(6), H-3(5) and H-3(4) levels. The most intensive band corresponds to the P-3(0)-F-3(2) transitions.