Abstract: The glass-forming region of GeS₂-Ga₂
S₃-KBr system glass was determined. The homogeneous glass containing KBr and
Ga₂S₃ up to 25mol% was prepared. The minimum content of GeS₂ for glass formation is 50mol%. Glass dehydration temperature
T_w, thermal expansion coefficient, ionic conductivity, optical transmission spectra and chemical durability of GeS₂-Ga₂S₃-KBr system glass were investigated. The experimental
results show that the highest characteristic temperatures of the glass are T_w>284.7℃, T_d=355℃, T_c=593℃ and ΔT=T_c-T_w>200℃. The optical
transmission of the glass is between 0.45 and 11.5μm. The transparent region of the glass shifts towards ultraviolet region by adding KBr. The
absorption bands at 3600, 2500 and 1600cm^-1 in infrared spectra can be assigned to the stretching vibration of O--H groups, the stretching
vibration of S-H groups and the bending vibration of H--O--H groups. The ionic conductivities of the glass are 10^-9～10^-12S/cm at 23℃,
10^-4～10^-6S/cm at 270℃. The chemical durability of GeS₂-Ga₂S₃-KBr system glass is satisfactory. The glass of GeS₂-Ga₂S₃-KBr system could be used as a potential candidate optical material
transmitting from visible to mid-infrared regions.

Key words: GeS₂-Ga₂S₃-KBr system glass, chalcohalide glass, glass-forming region, properties