NaF-LnF(3) binary systems and their complexes in molten state

This Study deals with the principal problems about complex compounds in the sodium fluoride-rare earth trifluoride systems. Phase diagrams, unit-cell dimension and refractive indices were reported for all the complex compound s in theses systems. Each of these system has, in addition to ifs end membr es, up to four crystalline phases. They are hexagonal NaF*LnF(3), cubic (fl uorite structure) NaF*LnF(3), which is completely miscible with cubic 5NaF* 9LnF(3) and ortorombic 5NaF*9LnF(3). Althought the cubic phases occur in a limited number ob binary systems. Our personal experimental data for the sy stem NaF- CeF3 (50-50 mol%) pointed our the cubic phase for the complex NaC eF4.