Synthesis and characterization of Sb/P substituted Ge-Ga-Se-Te bulk glasses

Mixed Se-Te glasses are unique materials for infrared optical applications due to their exceptional IR transparency, molding and fiber-drawing capability, environmental stability, and tailored physical properties. In this work, the effect of the gradual substitution of Sb with P in bulk P_xGa₅Ge₂₀Sb_10-xSe₄₅Te₂₀ glasses is studied with structural methods, optical spectroscopy, and differential scanning calorimetry (DSC). Non-isothermal and isothermal DSC studies reveal crystallization of several phases, some of them following the non-conventional anti-Arrhenius behavior of crystallization kinetics. The thermal stability of the glass is shown to increase with P concentration, and the glasses with x = 7, 9, 10 do not fully crystallize during the regular DSC heating scans. Their time-temperature-transformation curves reveal a known "nose"-like shape, suggesting crystallization at close proximity to the melting points of corresponding crystalline phases. It is found that the substitution of Sb with P in glass composition leads to a slight decrease in the optical gap and shift of the main Raman signal at ~ 150 cm^-1 to higher wavenumbers.