Synthesis, structure refinement and characterisation of a new oxyphosphate Mg{sub 0.50}TiO(PO{sub 4})
- LCMS, UFR Sciences des Materiaux Solides, Faculte des Sciences Ben M' Sik, Casablanca (Morocco)
- Departement de Chimie, Faculte des Sciences, Ain Chock, Casablanca (Morocco)
- Institut de chimie de la matiere condensee de Bordeaux (ICMCB-CNRS UPR 9048), 87, av. du Dr. A. Schweitzer, 33608 Pessac (France)
- Department of Chemistry, University of Pretoria, 0002 Pretoria (South Africa)
A new titanium oxyphosphate Mg{sub 0.50}TiO(PO{sub 4}) has been synthesized and characterized by several physical techniques: X-ray diffraction, {sup 31}P MAS-NMR, Raman diffusion, infrared absorption and diffuse reflectance spectroscopy. It crystallizes in the monoclinic system with unit cell parameters: a = 7.367(9), b = 7.385(8), c = 7.373(9) A, {beta} = 120.23(1), with the space group P2{sub 1}/c (no. 14), Z = 4. The crystal structure has been refined by the Rietveld method using X-ray powder diffraction. The conventional R indices obtained are R {sub wp} = 0.138, R {sub p} = 0.096 and R {sub B} = 0.0459. The structure of Mg{sub 0.50}TiO(PO{sub 4}) consists of infinite chains of corner-shared [TiO{sub 6}] octahedra parallel to the c-axis, crosslinked by corner-shared [PO{sub 4}] tetrahedra. These infinite chains have alternating short (1.74 A) and long (2.26 A) Ti-O bonds and are similar to those found in titanium oxyphosphate M{sup II} {sub 0.50}TiO(PO{sub 4}) (M{sup 2+} = Fe{sup 2+}, Co{sup 2+}, Ni{sup 2+}, Cu{sup 2+}, Zn{sup 2+}). The magnesium atom is located in an antiprism between two [TiO{sub 6}] octahedra. {sup 31}P MAS NMR showed only a single {sup 31}P resonance line, in a good agreement with the crystal structure. Raman and IR spectra show strong bands respectively at 765 and 815 cm{sup -1}, attributed to the vibration of -Ti-O-Ti-O- bonds in the infinite chains. The gap due to the Oxygen-Titanium(IV) charge transfer is 3.37 eV.
- OSTI ID:
- 21000637
- Journal Information:
- Materials Research Bulletin, Vol. 42, Issue 5; Other Information: DOI: 10.1016/j.materresbull.2006.08.020; PII: S0025-5408(06)00346-1; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
- Country of Publication:
- United States
- Language:
- English
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