VO2 (A) : reinvestigation of crystal structure, phase transition and crystal growth mechanisms
MICLAU, Marinela
National Institute for Research and Development in Electrochemistry and Condensed Matter [NIRDElCM]
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National Institute for Research and Development in Electrochemistry and Condensed Matter [NIRDElCM]
Langue
en
Article de revue
Ce document a été publié dans
Journal of Solid State Chemistry. 2014, vol. 213, p. 79-86
Elsevier
Résumé en anglais
Well crystallized VO2 (A) microrods were grown via a single step hydrothermal reaction in the presence of V2O5 and oxalic acid. With the advantage of high crystalline samples, we propose P4/ncc as an appropriate space group ...Lire la suite >
Well crystallized VO2 (A) microrods were grown via a single step hydrothermal reaction in the presence of V2O5 and oxalic acid. With the advantage of high crystalline samples, we propose P4/ncc as an appropriate space group at room temperature. From morphological studies, we found that the oriented attachment and layer by layer growth mechanisms are responsible for the formation of VO2 (A) micro rods. The structural and electronic transitions in VO2 (A) are strongly first order in nature, and a marked difference between the structural transition temperatures and electronic transitions temperature was evidenced. The reversible intra- (LTP-A to HTP-A) and irreversible inter- (HTP-A to VO2 (M1)) structural phase transformations were studied by in-situ powder X-ray diffraction. Attempts to increase the size of the VO2 (A) microrods are presented and the possible formation steps for the flower-like morphologies of VO2 (M1) are described.< Réduire
Mots clés en anglais
Hydrothermal synthesis
Vanadium dioxide polymorphs
Crystal growth
Structural and electronic transitions
X-ray photoelectron spectroscopy
Origine
Importé de halUnités de recherche