2003/01/24 by Z. V. Popovic, Z.V. Popovi, M.J. Konstantinovi +5
Chemical Engineering · Chemistry · Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Catalysis and Oxidation Reactions #Charge (physics) #Charge ordering #Chemistry #Condensed matter physics #Delocalized electron #Materials science #Molecular physics #Optics #Phonon #Physics #Raman scattering #Raman spectroscopy #Spectral line #Transition Metal Oxide Nanomaterials #Valence (chemistry) #X-ray Raman scattering #Zigzag #cond-mat.str-el
paper · pdf · doi:10.1088/0953-8984/15/6/101
5 pages, 4 figs incl. in the text. J.Phys.:Condens.Mater 15, (2003) in press
arxiv created 2003/01/24 · openalex publication_date 2003/02/03 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Polarized Raman spectra of the calcium vanadium oxide bronze β-Ca 0.33 V 2 O 5 are measured in the temperature range between 300 and 20 K. The charge ordering phase transition at about 150 K is characterized by the appearance of new Raman-active modes in the spectra, and by anomalies in the electronic background scattering. The high-temperature Raman scattering spectra of β-Ca 0.33 V 2 O 5 show an apparent resemblance to those of α'-NaV 2 O 5 , which suggests that the charge–phonon dynamics of the two compounds are similar. A study of the dynamical properties and a symmetry analysis of the Raman modes show that in the mixed-valence state of β-Ca 0.33 V 2 O 5 the electrons are delocalized into V 1 – O 5 – V 3 orbitals. We propose that in the charge ordered state below 150 K the d electrons localize within V 1 – V 3 ladders, either in a 'zigzag' fashion as in α'-NaV 2 O 5 or in the form of double chains as in γ-LiV 2 O 5 .