Thermodynamic modeling of the LiF-YF3 phase diagram

TL;DR

This paper presents a thermodynamic model of the LiF-YF3 phase diagram by fitting Gibbs energy functions to experimental data, including new thermoanalytic measurements, to accurately describe phase interactions and properties.

Contribution

It introduces a thermodynamic optimization method for the LiF-YF3 phase diagram using experimental data and Redlich-Kister polynomial for interaction modeling.

Findings

Calculated phase diagram agrees with experimental data

Thermodynamic properties of LiYF4 are accurately modeled

Interaction effects in the liquid phase are effectively described

Abstract

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.