Crystal data for two orthorphosphates α-NaCuPO4and β-AgCuPO4

Abstract

Two orthophosphates M1CuPO4 (with M1 = Na or Ag) have been synthesized by solid-state reaction between M3PO4 and Cu3(PO4)2. Each of these compounds undergoes a phase transition at high temperature, for AgCuPO4 the polymorphic transformation is irreversible. α-NaCuPO4 (low temperature) is orthorhombic P212121, a = 9.7098(8), b = 4.8040(3), c = 7.1676(6) Å, V = 334.34(7) Å3, Dm (298 K) = 3.55, Dx = 3.606 Mg m−3, Z = 4. β-AgCuPO4 (high temperature) is orthorhombic, Pbca, a = 7.5008(6), b = 15.749(1), c = 5.7030(5) Å, V = 673.70(14) Å3, Dm(298 K) = 5.25, Dx = 5.253 Mg m−3 for Z = 8. Powder diffraction data have been obtained at 293 K with a counter diffractometer with Ni-filtered copper radiation (λ = 1.5418 Å). The JCPDS Diffraction File Nos. are 34-1496 for β-AgCuPO4; 34-1497 for α-NaCuPO4.