Two novel Mo(V) and Mo(V)/Mo(VI) barium phosphates with a tunnel structure: β-Ba(MoO)2(P2O7)2, and Ba(MoO)2O(P2O7)PO4
| Autor: | André Leclaire, Valerie Pralong, Bernard Raveau |
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| Rok vydání: | 2005 |
| Předmět: |
Inorganic chemistry
chemistry.chemical_element Barium Crystal structure Condensed Matter Physics Magnetic susceptibility Electronic Optical and Magnetic Materials Inorganic Chemistry Crystallography chemistry Octahedron Group (periodic table) Materials Chemistry Ceramics and Composites Tetrahedron Physical and Theoretical Chemistry |
| Zdroj: | Journal of Solid State Chemistry. 178:1406-1413 |
| ISSN: | 0022-4596 |
| DOI: | 10.1016/j.jssc.2005.02.007 |
| Popis: | Two new Mo(V) and Mo(V)/Mo(VI) phosphates, β-Ba(MoO)2(P2O7)2 and Ba(MoO)2O(P2O7)PO4, with original tunnel structures have been synthesized. The first one crystallizes in the space group P21/n with a = 8.004 A , b = 7.899 A , c = 9.539 A , β = 91.67 ° , and the second one in the space group Cc with a = 13.020 A , b = 9.686 A , c = 8.636 A , β = 99.50 ° . β-Ba(MoO)2(P2O7)2 shows close relationships with the α-form, i.e., it consists of similar MoP2O11 units sharing their apices and forming [MoP2O10]∞ chains. It differs from the latter by the configuration of the chains, so that one chain is linked to four other identical chains, instead of six chains in the α-form. Like the α-form, the β-form exhibits intersecting tunnels running along [010] and [011] direction where the Ba2+ cations sit. The 3D-framework of the second phosphate Ba(MoO)2O(P2O7)PO4, is built up of MoO6 octahedra, P2O7 groups, and PO4 tetrahedra, can be described by the assemblage of zig-zag [Mo2P2O14]∞ chains through PO4 tetrahedra, forming large tunnels running along c ⇒ , occupied by Ba2+ cations. In this framework one observes that adjacent tunnels communicate through large six-sided windows, showing the opened character of this structure. The magnetic behaviour of these phosphates is discussed with respect to the results previously obtained by Canadell et al. [Chem. Mater. 9 (1997) 68]. |
| Databáze: | OpenAIRE |
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