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

A series of new glasses in the PbBr2–PbCl2–PbF2–PbO–P2O5 systems have been prepared and some properties studied. The composition dependence of density, glass transition temperature (Tg), thermal expansion coefficient, water durability and optical transmission is reported. A glass in the PbBr2–PbCl2–P2O5 ternary system has glass transition temperature as low as 146°C and density as high as 4.75 g/cm3. When PbO and/or PbF2 are introduced into the PbBr2–PbCl2–P2O5 system, the glass transition temperature and density of glasses grow higher obviously. The glasses in the PbBr2–PbCl2–PbF2–PbO–P2O5 system have density up to 5.84 g/cm3. 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 PbF2 into the glasses does not have much influence on their water resistance and weathering durability. The glasses in the PbBr2–PbCl2–P2O5 system have relatively high thermal expansion coefficient (25×10−6/°C).