Phase equilibria in the ErPO4-KPO3-Er(PO3)3 partial system

Phase equilibria in the ErPO4-KPO3-Er(PO3)(3) partial system were established, and the primary crystallization fields of the phosphates occurring in the composition range of ErPO4, KErP2O7, KPO3, Er(PO3)(3), KEr(PO3)(4) were defined. Two polythermal binary cross-sections, KErP2O7-Er(PO3)(3) and KErP2O7-KEr(PO3)(4), which are quasi-binary only in the subsolidus region (i.e. below 855 degrees C and 640 degrees C, respectively), were determined, and their phase diagrams were elaborated. Three invariant points, two ternary peritectics P-1 (855 degrees C) and P-2 (640 degrees C) as well as one ternary eutectic E (530 degrees C) were found in the ErPO4-KPO3-Er(PO3)(3) system. Alloy crystallization ends with the solidification of the ternary eutectic (KErP2O7 + KEr(PO3)(4) + KPO3). The studies were carried out by thermoanalytical methods (DSC/TG) and powder X-ray diffraction analysis (PXRD).

Automated summary

Phase equilibria and primary crystallization fields were established in the ErPO4-KPO3-Er(PO3)(3) partial system. Two polythermal binary cross-sections and three invariant points were determined, with the alloy crystallization ending in a ternary eutectic. The studies were conducted using thermoanalytical methods and powder X-ray diffraction analysis.