XPS, DRUV-VIS and ESR characterization of the non-stoichiometric compound Ge$_{0.74}$V$_{0.21}$ $\square_{0.05}$O$_{2}$

J.L. Boldú, J. Barreto, I. Rosales, L. Bucio, E. Orozco

Abstract


Microcrystalline powders of the nonstoichiometric Ge$_{0.74}$V$_{0.21}$ $\square_{0.05}$O$_{2}$ 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 V$^{4+}$ and V$^{5+}$ vanadium ions, the DRUV-VIS spectra show absorption bands in the 200-800 nm wave length interval and the ESR analysis confirms that the V$^{4+}$ ions are within microcrystals, hosted as VO$^{2+}$ at sites of rhombic (C$_{2v}$) symmetry.

Keywords


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

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Revista Mexicana de Física

ISSN: 2683-2224 (on line), 0035-001X (print)

Bimonthly publication of Sociedad Mexicana de Física, A.C.
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