Properties of lead–halide glasses in the PbBr2–PbCl2–PbF2–PbO–P2O5 system

Abstract A series of new glasses in the PbBr 2 –PbCl 2 –PbF 2 –PbO–P 2 O 5 systems have been prepared and some properties studied. The composition dependence of density, glass transition temperature ( T g ), thermal expansion coefficient, water durability and optical transmission is reported. A glass in the PbBr 2 –PbCl 2 –P 2 O 5 ternary system has glass transition temperature as low as 146°C and density as high as 4.75 g / cm 3 . When PbO and/or PbF 2 are introduced into the PbBr 2 –PbCl 2 –P 2 O 5 system, the glass transition temperature and density of glasses grow higher obviously. The glasses in the PbBr 2 –PbCl 2 –PbF 2 –PbO–P 2 O 5 system have density up to 5.84 g / cm 3 . Most of the glasses exhibit good water resistance and good weathering durability. The dissolution rate in deionized water at 25°C is in the order of 10 −4 –10 −5 mm/day. The introduction of PbO and/or PbF 2 into the glasses does not have much influence on their water resistance and weathering durability. The glasses in the PbBr 2 –PbCl 2 –P 2 O 5 system have relatively high thermal expansion coefficient (25×10 −6 /°C).