Rietveld refinements of the solid solution Li(1-2x)NixTiO(PO4) (O ≤ x ≤ 0.50).
Langue
en
Article de revue
Ce document a été publié dans
Materials Research Bulletin. 2005, vol. vol. 40, n° 2, p. p. 229-238
Elsevier
Résumé en anglais
Li(1−2x)NixTiO(PO4) oxyphosphates with 0 ≤ x ≤ 0.10 crystallize in the orthorhombic system with the space group Pnma, those with 0.10 < x ≤ 0.25 crystallize in the monoclinic system with the space group P21/c and compositions ...Lire la suite >
Li(1−2x)NixTiO(PO4) oxyphosphates with 0 ≤ x ≤ 0.10 crystallize in the orthorhombic system with the space group Pnma, those with 0.10 < x ≤ 0.25 crystallize in the monoclinic system with the space group P21/c and compositions with 0.25 < x < 0.50 present a mixture of the limit of the solid solution Li0.50Ni0.25TiO(PO4) and Ni0.50TiO(PO4). The structure of the compositions 0 ≤ x ≤ 0.25 is based on a three-dimensional anionic framework constructed of chains of alternating TiO6 octahedra and PO4 tetrahedra, with the lithium and nickel atoms in the cavities in the framework. The dominant structural units in the compositions are chains of tilted corner-sharing TiO6 octahedra running parallel to one of the axis. The oxygen atoms of the shared corners, not implied in (PO4) tetrahedra, justify the oxyphosphate designation. Titanium atoms are displaced from the geometrical center of the octahedra resulting in alternating long (≈2.25 Å) and short (≈1.71 Å) Tisingle bondO(1) bonds. The four remaining Tisingle bondO bond distances have intermediate values ranging from 1.91 to 2.06 Å.< Réduire
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X-ray diffraction
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