Cubic pyrochlore of the composition Bi2Ni1/2Co1/2Ta2O9 ± ? (sp. gr. Fd-3m, a = 10.5261(8) ?) was synthesized for the first time from the corresponding oxides by the solid-phase reaction method. The complex oxide is characterized by a porous microstructure formed by partially fused elongated crystallites with an average longitudinal size of 1…2 ?m. The chemical state of transition element cations in pyrochlore was characterized by photoelectron spectroscopy (XPS) and NEXAFS.
A characteristic shift of the Ta4f spectrum toward lower energies by 0.8 eV is observed for pyrochlore, due to which the effective charge of tantalum cations is +(5 – ?). The absorption spectrum of pyrochlore in the region of the Co2p absorption edge is a superposition of the spectra of CoO and Co3O4. According to the nature of XPS, NEXAFS Ni2p spectra, nickel ions are in the Ni (II, III) state.
Kristina N. Parshukova – bachelor of Chemistry Department, Pitirim Sorokin Syktyvkar State University, Syktyvkar, Russia
Sergey V. Nekipelov – Candidate of Physical and Mathematical Sciences, Head Laboratory of Experimental Physics, Institute of Physics, and Mathematics of Komi Science Center UB RAS, Syktyvkar, Russia
Nadezhda A. Zhuk – Candidate of Chemical Sciences, Associate Professor, senior researcher of Laboratory of Ceramic Materials Science, Pitirim Sorokin Syktyvkar State University, Syktyvkar, Russia
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