  A thermodynamic optimization of the LiF-YF3 binary phase diagram was
performed by fitting the Gibbs energy functions to experimental data that were
taken from the literature, as well as from own thermoanalytic measurements (DTA
and DSC) on HF-treated samples. The Gibbs energy functions for the end member
compounds were taken from the literature. Excess energy terms, which describe
the effect of interaction between the two fluoride compounds in the liquid
phase, were expressed by the Redlich-Kister polynomial function. The calculated
phase diagram and thermodynamic properties for the unique formed compound,
LiYF4, are in reasonable agreement with the experimental data.
