A study on the phase diagram of A1F3-CsF system

Article abstract of DOI:10.1016/s0040-6031(97)00236-0

Phase relations of the AlF₃-CsF system have been investigated by the methods of DTA and XRD with quenching technique. Four compounds were identified: Cs₃AlF₆, CsAlF₄, CsF·2AlF₃ and CsF·3AlF₃. Cs₃AlF₆ melts congruently at 790°C. The first eutectic, E₁, between Cs₃AlF₆ and CsF is located in 10.0 mol% AlF₃ at 654°C. CsF-2AlF₃ and CsF-3AlF₃ melt incongruently at 508° and 653°C, respectively. The second eutectic, E₂, was observed in 42.0 mol% AlF₃ at 471°C. The compound CsAlF₄ formed in the solid eutectic when cooled below 443°C. CsAlF₄ has α and β forms, transformation of which takes place reversibly at 422°C. All phase structures in the system were confirmed by X-ray powder diffraction analysis.