Neue Phosphate mit Eulytinstruktur,insbesondere Europium(II)-Verbindungen [1]

New Phosphates with Eulytine Structure, especially Europium(II) Compounds. A number of Eu(II) phosphates EuLn(PO₄)₃ have been prepared, where Ln? La, lanthanides, Y. All investigated compounds have colours from yellow to ockre and crystallize with the cubic structure of eulytine (Bi₄(SiO₄)₃). Eu(PO₄)₃ makes an exception, showing a lattice deformation to low symmetry. It converts to a cubic eulytine phase by partial oxydation. The peculiar run of the lattice constants of the Eu(II) compounds in the lanthanide series is compared with the behaviour of the analogous Sr, Pb, and Ba compounds. Moreover, the eulytine compounds Pb₃M^III(PO₄)₃ with M^III? V, Cr, Fe have been synthesized. Experiments with Ti^III yield solid solutions between Pb₃Ti^III(PO₄)₃ and Pb₇Ti^IV(PO₄)₆.