Atomic Modeling of the δ ⇔ ε LiV2O5 Phase Transition and Simulation of the XRD Powder Pattern Evolution
✍ Scribed by Jean Galy; Christine Satto; Philippe Sciau; Patrice Millet
- Publisher
- Elsevier Science
- Year
- 1999
- Tongue
- English
- Weight
- 421 KB
- Volume
- 146
- Category
- Article
- ISSN
- 0022-4596
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✦ Synopsis
LiV 2 O 5 crystallize in the orthorhombic system, with Cmcm and Pmmn space groups, respectively. Transformation of into is initiated at about approximately 1103C. In both structures, lithium atoms are intercalated between [V 2 O 5 ] n layers built up by VO 5 square pyramids sharing edges and corners, these layers being alternatively half shifted along the 3.6 A > parameter in the phase. Both crystal structures have been accurately depicted using Pmn2 1 space group with the short parameter along c. The phase transition, corresponding to a slip of c/ 2 of the alternate [V 2 O 5 ] n layer of together with some lithiums, has been modeled step by step in order to be aligned along c, to 5nally match the structural organization. The shift vector s applied to z coordinates varies from 04 4s4 40.5. The resulting evolution of the sequence of the computed X-ray powder pattern compares well with the experimental one done at ESRF ( ؍ 0.64667). The joint structural modeling and X-ray patterns account for the 0 0 LiV 2 O 5 phase transition.