Abstract

BOLDU, J.L. et al. XPS, DRUV-VIS and ESR characterization of the non-stoichiometric compound Ge_0.74V_0.21 □_0.05O₂. Rev. mex. fis. [online]. 2017, vol.63, n.2, pp.166-170. ISSN 0035-001X.

Microcrystalline powders of the nonstoichiometric Ge0.74V0.21 □0.05O2 compound were prepared by conventional high temperature solid-state reactions. The powders were characterized by X-ray diffraction (XRD); scanning electron microscopy (SEM); X-ray photoelectron spectroscopy (XPS); diffuse reflectance ultraviolet-visible spectroscopy (DRUV-VIS) and electron spin resonance (ESR) spectroscopy. From the analysis performed on compound, it was found that: The powders showed a rutile type crystalline structure with a rectangular prismatic crystalline habit. The XPS analysis, confirm the presence of V4+ and V5+ vanadium ions, the DRUV-VIS spectra show absorption bands in the 200-800 nm wave length interval and the ESR analysis confirms that the V4+ ions are within microcrystals, hosted as VO2+ at sites of rhombic (C 2v ) symmetry.

Keywords : Crystal Stoichiometry; X-ray powder diffraction; SEM; XPS; DRUV-VIS; ESR.

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