Synthesis of new network phosphates with NZP structure

New NZP-type phosphates of the formula PbM3+M4+P3O12 (M3+ = Cr, Fe, and In; M4+ = Ti, Zr, Hf, and Sn) were synthesized. The evolution of lattice param eters with radii of M3+ and M4+ cations indicates the anomalous behavior of tin-containing compounds. The room temperature structure of PbFeZrP3O12 ha s been refined using powder neutron diffraction data. The compounds were ch aracterized by infrared and electronic spectroscopic methods. Pb0.5Mo2P3O12 with molybdenum present in the reduced state (+4) was synthesized. It is f ound that Pb0.5Mo2P3O12 is structurally related to TlMo2P3O12 and crystalli zes in an orthorhombic system with parameters a = 8.62.1 Angstrom; b = 9.49 2 Angstrom; c 12.486 Angstrom. (C) 1999 Academic Press.