Thermal Analysis and Phase Equilibria of the Molten System Na3AlF6-NdF3-Nd2O3

Phase diagrams of the systems Na3AlF6-NdF3 and (Na3AlF6-NdF3)(eut)-Nd2O3 were experimentally determined by thermal analysis up to 60 mol.% NdF3 and 45 mol.% Nd2O3, respectively. The Na3AlF6-NdF3 system was found to be a simple eutectic system with the eutectic point with the following approximate coordinates: 49 mol.% NdF3 and 905(circle)C. This eutectic composition was then used for the thermal analysis of the (Na3AlF6-NdF3)(eut)-Nd2O3 system. The coordinates of the eutectic point of the (Na3AlF6-NdF3)(eut)-Nd2O3 system were found to be approximately 46 mol.% Nd2O3 and 733(circle)C. After the thermal analysis, the x-ray diffraction analysis of the solidified samples of both systems was performed. The XRD analysis of the Na3AlF6-NdF3 system has shown the formation of two new compounds; NaNdF4 and NdOF. The formation of NdOF is probably the product of the high-temperature hydrolysis between the moisture in the atmosphere and NdF3. The XRD analysis of the solidified samples of the (Na3AlF6-NdF3)(eut)-Nd2O3 system has shown the formation of the following new compounds: NaNdF4, NdOF, NdAlO3, and NaF.

Automated summary

Phase diagrams of Na3AlF6-NdF3 and (Na3AlF6-NdF3)(eut)-Nd2O3 systems were determined by thermal analysis. XRD analysis of the solidified samples showed the formation of new compounds in both systems.