Crystallization And Phase Separation In Fluoride Glasses

Abstract

We report here two studies relevant to these phenomena. Phase separation was unambiguously shown to occur in a ZrF₄-based glass containing a small amount of PbF₂ and prepared under a chloride-containing reactive atmosphere. Partial replacement of ZrF₄ by HfF₄ in a ZBLAN glass appears to improve the resistance to crystallization. The reason for this improvement seems to be a change in the crystalline phases and compositions first appearing on reheating.