ISSN:
1434-6036
Keywords:
PACS. 61.50.Nw Crystal stoichiometry – 71.28.+d Narrow-band systems; intermediate-valence solids – 78.70.Dm X-ray absorption spectra
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract: The valency of vanadium, and thus indirectly the oxygen stoichiometry, of V-doped hafnia synthesized under different atmospheres have been investigated on a nanometer scale by means of electron energy loss spectroscopy (EELS). The EELS V L2,3 spectra are compared with the results of crystal field multiplet calculations and experiments on reference vanadium oxides. The EELS spectra indicate that V-doped hafnia prepared under reducing (H2) and neutral (Ar) atmosphere are unambiguously substituted with trivalent vanadium atoms leading to the creation of oxygen vacancies in the structure. On the contrary, stoichiometric (Hf, V)O2 compound (i.e. V4+) is more likely to be stabilized under oxidative (air) atmospheres. We also show that the amount of hybridization alters for the different compounds studied but may in part be analyzed by high spatially resolved EELS. The crystal field multiplet calculations particularly indicate that a simple reduction of the Slater integrals gives a good account of the spectral modification induced by hybridization for the case of tetravalent vanadium atoms.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/PL00011142
