Crystal Chemistry of Cd2-xCuxP2O7, 0 ≤ x ≤ 2 Structure of CdCuP2O7

✍ Scribed by A.Alaoui El Belghiti; A. Elmarzouki; A. Boukhari; E.M. Holt

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 218 KB
• Volume: 109
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1994.1111

✦ Synopsis

The domains of the system, (\mathrm{Cd}{2-x} \mathrm{Cu}{\mathrm{x}} \mathrm{P}{2} \mathrm{O}{7}, \mathrm{O} \leq x \leq 2), have been established by powder diffraction methods. Two solid solutions have been found near (\mathrm{Cd}{2} \mathrm{P}{2} \mathrm{O}{7}(0 \leq x \leq 0.40)) and (\mathrm{Cu}{2} \mathrm{P}{2} \mathrm{O}{7}) ( (1.60 \leq x \leq 2) ). A new phase with (x=1) has been identified using single crystal (\mathrm{X})-ray diffraction. The mixed diphosphate (\mathrm{CdCuP}{2} \mathrm{P}{7}) ((x=1)) crystallizes in monoclinic space group (C 2) with (a=) 6.806(7), (b=8.665(4), c=4.504(2) \AA, \beta=105.85(6)^{\circ}, V=) 255.5(3) (\AA^{3}, \lambda(\mathrm{MoK} \alpha)=0.71069 \AA, \mu_{\mathrm{MoK} \alpha}=89.26 \mathrm{~cm}^{-1}), (D_{\text {calc }}=4.55 \mathrm{~g} \mathrm{~cm}^{-3}, D_{\text {meas }}=4.59(5) \mathrm{g} \mathrm{cm}^{-3}, Z=2, F(000)=) (326, T=298 \mathrm{~K}, R=3.9 %, R_{\mathrm{W}}=5.1 %) for 247 observed reflections. (\mathrm{P}{2} \mathrm{O}{7}) groups show staggered conformation identifying the solid state structure to be of the thortveitite type. The mixed (\mathrm{Cd}: \mathrm{Cu}) sites display sixfold coordination with average (M-\mathrm{O}) distance 2.24(3) Å. O 1994 Acadenic Press, Inc.