Modeling of the curve radial electronic density distribution for amorphousMe-Zr-O systems

Me-Zr-O systems were studied with X-ray Radial Electronic Density Distribut ion (RED) method. This method is based on the relation between the radial e lectronic density distribution function and intensity of coherent scatterin g of X-ray in the diffraction experiment. The intensity of scattering was m easured for a wide range of angles using monochromator and CuK alpha radiat ion. RED curves was made by resolving in sum of Gauss function. Data on the known oxides and hydroxides structures, such as interatomic distances (r) and coordination number (Z) were used for the calculated curves. The values r and Z were calculated from the data of structural type, spatial group, c oordinates of atoms and parameters of cell. For Fe-Zr-O system it has been demonstrated that all samples have similar structures, which related to tha t of cubic alpha-ZrO2. The model with statistical arrangement of Fe3+ catio ns, vacancies in the cation and anion sublattices and modification of anion sublattice with OH- groups is admitted as most probable. Numbers of cation and anion vacancies and number of OH- groups were evaluated using experime ntal RED curves of samples. (C) 2000 Elsevier Science B.V. All rights reser ved.