III International Conference

PP-II-54THE APPLICATION OF WAXS METHOD FOR CHARACTERIZATION OF PHASECOMPOSITION AND LOCAL STRUCTURE OF MULTYCOMPONENT HIGHLYDISPERSED SYSTEMSKolko V.P., Moroz E.M., Zuyzin D.A., Shefer K.I., Kogan V.A.Boreskov Institute of Catalysis SB RAS, Novosibirsk, RussiaE-mail: emoroz@catalysis.ruThe method of wide-angle X-ray scattering (WAXS) in details is described elsewhere [1].The application of WAXS method for characterization of phase composition and investigationof local structure is based on using of X-ray scattering measured in wide angle range andsubjected to the Fourier transformation. The analysis is reduced to detection on radialelectronic density distribution curve of coordination peaks corresponded to interatomicdistances, which are typical for studied phases. This analysis could be carried out even forphases with coherent scattering regions less then 50 Å. For the proposed phase compositionone may calculate model WAXS curve and compare it with one calculated from experimentalX-ray diffraction pattern. Using of WAXS method and calculation of model curves gives achance to define changes in local structure of the studied phases in comparison with themonocrystal analogue [2]. Overall model curve might be decomposed in partial ones,responded to separate fragments of the structure or certain pairs of atoms. Such information isnecessary for determination of changes in local structure and defects.X-ray diffraction patterns were obtained on high resolution diffractometer at theSynchrotron Radiation Center (Budker Institute for Nuclear Physics of the Siberian Branch ofthe Russian Academy of Science) with extraction of monochromatic radiation on diffractionbeam from crystal-monochromator Si (1.1.1) (degree of monochromatization is aboutΔλ/λ~10 -4 ).The numerous examples of characterization of phase composition and local structure ofmultycomponent highly dispersed systems using the model WAXS curves are considered:aluminium hydroxides obtained by different technologies, highly dispersed (crystalline sizeabout 50Å) complex oxide systems Me-Ce-O, where Me=Gd, Pr, Zr аnd different supportedmetallic catalysts.References1. E.M. Moroz: Rus Chem. Rev. 61 (1992) 1882. Ella M. Moroz, Kristina I. Shefer, Dmitry A. Zyuzin, Aleksandra S. Ivanova, Eugenia V.Kulko, Vasily V. Goidin and Viktor V. Molchanov. React. Kinet. Catal. Lett. 87 (2006) 367.262