6533b851fe1ef96bd12a8c11
RESEARCH PRODUCT
Stability of non-stoichiometric laof phases: x-ray diffraction investigation
Hanna RahialaH HolsaJussi ValkonenEija Säilynojasubject
Diffractionchemistry.chemical_compoundCrystallographyTetragonal crystal systemValence (chemistry)chemistryX-ray crystallographyMaterials ChemistryCrystal structureCrystalliteFluorideSolid solutiondescription
Summary The X-ray diffraction patterns of the polycrystalline LaO 1−x F 1+2x (0.05≤x≤0.3) phases were measured at room temperature and analyzed by the Rietveld profile refinement method. All compounds crystallize in the tetragonal PbFCl-type structure with P4/nmm as the space group. No distortion to lower orthorhombic symmetry was observed. The tetragonal lattice parameters a and c increase with increasing excess of fluoride. The La-oxygen (La-fluorine) distances first decrease (increase) but then these trends are reversed. The Global Instability Index calculated from the bond valence model increases towards the higher fluoride content of the compounds indicating decreasing stability
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1998-01-01 | Annales de Chimie Science des Mat�riaux |