Аннотация:The phase formation in Na3REE(PO4)2–Na3REE(VO4)2 (REE = Gd, Y) systems in the 873–
1573 K temperature range was investigated by XRD and DSC methods. Formation of two solid solutions
based on both compounds was revealed. Endothermic effects corresponding to structural phase transformations and melting of samples were registered.