272 research outputs found
X-ray powder diffraction study of chromium-vanadium oxide compounds prepared by "soft chemistry" methods
A novel aqueous method was used to synthesise mixed chromium-vanadium
oxide hydrates with various chromium content, via the reaction of
peroxo-polyacids of chromium and vanadium. The resulting materials are
gelatinous. The dehydration of the gels result in a brown coloured
amorphous powder. Depending on the chromium content, the compounds have
a different characteristic crystallisation temperature upon the further
heating. The crystalline compounds, except for the low chromium ones,
go on a phase transition and decompose with increasing temperature.
By refining the XRPD measurement data of the compounds, the type and
parameters of the unit cells were determined. The experimental data
were in concordance with the calculated values, using the PWC code. The
lattice parameters and the crystalline structure were changed with the
variation of chromium content. (C) Versita Warsaw and Springer-Verlag
Berlin Heidelberg. All rights reserved
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