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

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.

► Compounds in Ca10(PO4)6Cl2–Pb10(PO4)6Cl2 system were synthesized by solid state reaction.
► In the investigated system there are two fields because of the formation a compound with formula Ca7Pb3(PO4)6Cl2.
► The Pb10(PO4)6Cl2–Ca7Pb3(PO4)6Cl2 is characterized by unbounded mixing of components.
► The Ca7Pb3(PO4)6Cl2–Ca10(PO4)6Cl2 area has complicated character due to presence of decomposition processes.