Synthesis and physical properties of the system (GeS 2) 80− x(Ga 2S 3) 20: xPr glasses

Abstract

High purity (GeS 2) 80− x (Ga 2S 3) 20· xPrCl 3 ( x= 1,2,3), (GeS 2) 79(Ga 2S 3) 20Pr 6O 11 glasses were prepared and their basic thermal and optical properties were detemuned. The glass transition temperature T g is in the region 399–404°C. The glass-forming criteria (Δ T ∈ (123–128°C), H r ∈ (0.59–0.66), S ∈ (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 3H 4- 3H 6, 3H 4- 3F 3, 3H 4- 3F 4, 3H 4- 3P 0 and 3H 4- 3P 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 GeS 4 and GaS 4 tetrahedra vibrations. The narrow luminescence bands corresponding to electron transitions in Pr 3+ ions (20000, 17857, 15873, 15220, 14326, 13947 and 13459 cm −1) with the most intensive band near 15220 cm −1 were found. These bands can be assigned to the transitions from the 3P 0 and 1D 2 levels to 3F 4, 3F 3, 3F 2, 3H 6, 3H 5 and 3H 4 levels. The most intensive band corresponds to the 3P 0- 3F 2 transitions.