Glass Formation in the ZrF4–LaF3–BaF2–NaF System

The glass formation in the ternary ZrF4–LaF3–BaF2and quaternary ZrF4–LaF3–BaF2–NaF systems at a zirconium fluoride content of 50–60 mol % is investigated. The glass formation region in the ternary system has the shape of a petal and lies along the LaF3–BaZr2F10join. The glass formation regions in the quaternary system are either localized or continuous depending on the zirconium fluoride content. The glass transition temperatures Tgfall in the range 180–290°C, and the temperatures of the onset of crystallization lie in the range 250–340°C. Glasses crystallize in one, two, or three stages. The melting temperature varies in the range from 390 to 650°C. The microhardness of glasses is measured. The compositions of the most stable glasses are determined.