ALKALI FLUOROZIRCONATE GLASSES

Glass formation was investigated in fluoride systems based on ZrF4, in association with aluminum and zinc fluoride and containing large amou nts of alkali fluorides. Properties of the glasses including chemical durability in the 50(ZrF4-ZnF2-AIF(3))-5YF(3)-10BaF(2)-35LiF system we re measured. Then lithium fluoride was substituted by NaF and KF in th e 20ZrF(4)-10ZnF(2)-20AIF(3)-5YF(3)-10BaF(2)-35LiF glass. Finally, gla ss formation in the pseudo ternary system 85(ZrF4-NaF-LiF)-5AIF(3)-1OB aF(2) was investigated. Glasses with refractive index equal to 1.445 c ould be obtained. Glass transition a temperature ranges from 200 to 26 5 degrees C for glasses containing 35 to 45 mol% in alkali fluorides.