Glass formation in the PbBr2–PbCl2–PbF2–PbO–P2O5 system

New glasses in the PbBr2–PbCl2–PbF2–PbO–P2O5 system have been prepared and characterized. The glass-forming regions have been explored and the stability of the glasses against crystallization studied. Results show that the PbBr2–PbCl2–P2O5 ternary system has a broad glass-forming region which extends to 30 mol% P2O5. Most of the glasses in this system show strong stability against crystallization and some have glass transition temperatures as low as 146°C. When 5% PbO or 5% PbF2 is introduced into the PbBr2–PbCl2–P2O5 system, the glass-forming region becomes smaller and the glass transition temperatures increase. However, the introduction of 2.5% PbF2 and 2.5% PbO into the ternary system increases the glass transition temperature and broadens the glass-forming region. The introduction of PbF2 alone improves the glass-forming ability of the system while the introduction of PbO alone lowers the glass-forming ability.