Phase diagram of apatite system Ca₁₀(PO₄)₆Cl₂–Pb₁₀(PO₄)₆Cl

Compounds in Ca₁₀(PO₄)₆Cl₂–Pb₁₀(PO₄)₆Cl₂ system were synthesized by solid state reaction. It was ascertained using DTA and X-ray diffraction methods that in the investigated system there are two fields because of the formation a compound with formula Ca₇Pb₃(PO₄)₆Cl₂. The first area is the Pb₁₀(PO₄)₆Cl₂–Ca₇Pb₃(PO₄)₆Cl₂ which is characterized by unbounded mixing of components. The second Ca₇Pb₃(PO₄)₆Cl₂–Ca₁₀(PO₄)₆Cl₂ area has complicated character due to presence of decomposition processes. In spite of the presence of the one nature polymorphic transitions of Ca₁₀(PO₄)₆Cl₂ and Pb₁₀(PO₄)₆Cl₂ the same effects on all solid solutions were not observed.