39818-95-6Relevant academic research and scientific papers
Na//2Ca//3Al//2F//1//4: A NEW EXAMPLE OF A STRUCTURE WITH 'INDEPENDENT F** minus ' - A NEW METHOD OF COMPARISON BETWEEN FLUORIDES AND OXIDES OF DIFFERENT FORMULA.
Courbion, G.,Ferey, G.
, p. 426 - 431 (1988)
Na//2Ca//3Al//2F//1//4is cubic. The absolute configuration was determined from 1412 X-ray independent reflections. The structure contains isolated left bracket AlF//6 left bracket **3** minus octahedra and an independent fluoride ion, F//3, linked to three Ca**2** plus and one Na** plus ions. The tetrahedra left bracket FCa//3Na right bracket **6** plus linked by Ca**2** plus ions, build up a three-dimensional network in which the octahedral entities left bracket AlF//6 right bracket **3** minus are inserted. A structural analysis leading to a comparison with oxide structures is given for compounds containing 'independent' fluoride ions and isolated left bracket MF//6 right bracket octahedra, despite different chemical formulations for the fluorides and the corresponding oxides.
Structure of α-NaCaAlF6 determined ab initio from conventional powder diffraction data
Le Bail,Hemon-Ribaud,Courbion
, p. 265 - 272 (1998)
α-NaCaAlF6 is prepared by solid state reaction as poor quality crystals. The structure is determined ab initio from conventional X-ray powder data. The cell is monoclinic, space group P21/c, Z = 8, with a = 8.7423(3) A, b = 5.1927(2) A, c = 20.3514(9) A and β = 91.499(2)°. The final Rietveld refinement leads to RP = 10.6% and RB = 5.2%. The structure is built up from isolated AlF6 octahedra, interconnected by CaF7 polyhedra sandwiched between layers of NaF8 and NaF7 polyhedra extending in the be plane. Elsevier.
Thermal transformation of quaternary compounds in NaF-CaF2-AlF3 system
Zaitseva, Julia N.,Yakimov, Igor S.,Kirik, Sergei D.
, p. 2246 - 2251 (2009)
Details of quaternary compounds formation in the system NaF-CaF2-AlF3 are specified. To achieve this aim, the samples of phases NaCaAlF6 and Na2Ca3Al2F14 have been obtained by hi
