X 10 X-ray spectra and electronic structure of LixNbO2 superconductor and other niobium oxide compounds / V. M. Cherkashenko, M. A. Korotin, V. I. Anisimov, V. V. Shumilov, D. G. Kellerman, V. G. Zubkov, E. Z. Kurmaev // Zeitschrift für Physik B Condensed Matter. - 1993. - Vol. 93. - P417-424. - Bibliogr. : p. 424 (17 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ОКСИД НИОБИЯ -- ЛИТИЕВАЯ ПРОВОДИМОСТЬ Аннотация: X-ray emission NbL&.15 and OK~ spectra and Ols total photoelectron yield spectra for superconductor Li0.71NbO2 and other niobium oxide compounds NbO, BaNb406, BazNbsO9, BaNbsQ, LiNbQ, NbQ, LiNbO3 were investigated. It was found that in stoichiometric LiNbO2, niobium oxidation degree is 3 +. Under the lithium deintercalation down to Li0.71NbO2 composition, the niobium ions oxidation degree increases up to 3.3 +. As more electrons are supplied by Nb to fill the O2p band, the degree of O2p-Nb4d hybridization is increased. Using the full-potential linear muffin-tin orbital method, the self-consistent band structure calculations of Li~NbO 2 (x= 1.0; 0.7; 0.5) compounds were carried out. Agreement between partial Nb4d and O2p densities of states and corresponding X-ray spectra was observed. For the x = 0.7; 0.5 the Fermi level is placed on the slope of sharp density of states peak formed mostly by the Nb4d states. With the decrease of x the p-d hybridization becomes stronger, although remains well below the values typical for the high-temperature superconductors Полный текст |