Recognition on systems RbF–GaF3 and CsF–GaF3

The systems RbF–GaF3 and CsF–GaF3 were re-investigated by DTA and XRD method. In the system RbF–GaF3, with eutectic E1 at 750°C in the location of 8.5 mol% GaF3 and E2 at 749°C in the location of 43.0 mol% GaF3, three compounds Rb3GaF6, RbGaF4 and RbF·2GaF3 were identified and indexed by XRD. The indexed result of α-Rb3GaF6 could not be successfully obtained, β-Rb3GaF6 is tetragonal, a=6.324±0.004, c=8.860±0.003 Å. RbGaF4 is orthorhombic, a=9.821±0.006, b=9.517±0.005, c=8.060±0.006 Å; RbF·2GaF3 is also orthorhombic, a=9.459±0.005, b=9.336±0.005, c=7.685±0.005 Å. In the system CsF–GaF3, with eutectic E1 at 664°C in the location of 7.5 mol% GaF3 and E2 at 675°C in the position of 44.0 mol% GaF3, two compounds were confirmed. α-Cs3GaF6 is orthorhombic with a=10.62±0.02, b=9.959±0.006 and c=5.607±0.005 Å; β-Cs3GaF6 is also orthorhombic, a=10.356±0.003, b=8.280±0.003, c=7.621±0.005 Å; γ-Cs3GaF6 is tetragonal, a=6.833±0.003, c=9.869±0.002 Å; CsGaF4 is orthorhombic, a=8.571±0.007, b=7.575±0.007 and c=6.981±0.006 Å.