Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
673914 | Thermochimica Acta | 2013 | 5 Pages |
Differential thermal analysis up to complete melting was thoroughly performed for the pseudobinary system LiF–BiF3. Melts with high bismuth fluoride concentration suffered from high evaporation; nevertheless even pure BiF3 could be molten at 655 °C. The system contains one intermediate compound BiLiF4 which melts by peritectic decomposition with the formation of LiF at 450 °C. The eutectic between BiLiF4 and BiF3 melts at 415 °C. Thermodynamic assessment yielded the following parameters for BiLiF4: ΔH = −1, 514, 900 J mol−1, S = 158.5 J mol−1 K−1, cp = 166.173 − 0.01072 · T (in J mol−1 K−1). The melt has negative excess Gibbs free energy.
► The LiF–BiF3 phase diagram is described and assessed for the first time. ► Intermediate compound BiLiF4 melts incongruently with peritectic formation of LiF. ► Density disparity between components leads to non-equilibrium effects.