Solid State Phenomena Vol. 163

Abstract: EXPO2009 [1], the updated version of EXPO2004 [2], performs all the steps for the ab-initio crystal structure solution by powder diffraction data in a completely automatic way: unit cell determination, space group identification, decomposition of the experimental pattern into single integrated intensities, structure solution by traditional (Direct/Patterson) or direct space/hybrid approaches, structure refinement by Rietveld techniques [3]. New procedures have been introduced in EXPO2009 to strengthen its phasing ability, especially for organic compounds and for low resolution data, for which traditional approaches may fail.

Abstract: Electrodeposition and other methods are employed to obtain metallic films and coatings. Copper coatings are most extensively used in circuit board industry and often as a base to further formation of other metallic films. Electrodeposited copper films (thin layers) are widely used in electronic and automotive industry so its electrical and mechanical properties and its thickness are important. Several methods are used for thickness determination of thin films and coatings for example mechanical, magnetic and ball crater with light microscopy methods. They are destructive and not precise enough. The X-ray fluorescence, absorption and diffraction are more frequently used due to better precision. Although they are complex and expensive, they pronounce an important feature like non-destructive character. For particular cases geometrical conditions and mathematical calculation procedure must be elaborated. An application of X-ray diffraction in grazing incidence angle for thickness determination is described in this article. The method is based on absorption principles of X-ray beam. The absorption is proportional to thickness of the coating and to incidence and to the diffraction angle which. Geometrical conditions were obtained experimentally and suitable mathematical calculations were introduced. The elaborated methodical approach was applied to thickness determination of copper coatings electrodeposited on a brass substrate.

Abstract: Orientation mapping in transmission electron microscope was successfully applied to study microstructural changes at the initial stage of recrystallization in the aluminum alloy with a bimodal second-phase particle distribution. The alloy samples were reversibly cold rolled resulting in the formation of laminar structure with zones of localized strain around large second-phase particles. Orientation mapping and in-situ investigations carry information about the processes which are active in the deformation zones during annealing.

Abstract: Recent advances in Line Profile Analysis of powder diffraction patterns must be paralleled by increasing attention to the quality and quantity of experimental data. The analysis of simulated data with different noise levels demonstrates the importance of statistical quality to reveal fine details of interest in the analysis of nanocrystalline materials, like the crystallite shape. It is also shown how synchrotron radiation diffraction can improve data quality with respect to laboratory measurements, both in terms of statistical quality and in terms of accessible information.

Abstract: This work shortly describes the morphology of polymers and presents the possibilities of SAXS method in the investigations of the structure of polymers referring to our studies on the structure of homogeneous copolymers ethylene-1-octene. Besides, we describe our computer program SAXSDAT designed for the analysis of SAXS curves of polymers.

Abstract: Steelmaking dust, collected from four different steel plants, was examined by X-ray diffrac-tion powder technique using phase analysis. Some lead compounds, namely oxides, a silicate, a sul-phate and a chloride hydroxide, were identified. The quantities of the main phase components as franklinite, magnetite, hematite and zincite were determined, applying the Rietveld method. The importance of application of the microabsorption correction was shown.

Abstract: Strontium cobaltite doped with Fe and Nb, SrCo0.6Fe0.2Nb0.2O3−z, with perovskite-like structure, being one of the promising materials for oxygen permeable membrane implementation, has been investigated via in situ high temperature X-ray powder diffraction on Bruker D8 Advance instrument and high-resolution powder diffraction at synchrotron radiation beamline. The oxygen outlet from the lattice has been found to stay in correlation with the structural rearrangement forming two phases with different oxygen deficiency. The activation energy of phase splitting process has been estimated to be Eactivation ≈ 0.63 ± 0.06 eV.

Abstract: The effect of rapid solidification on the microstructure of Al-Zn-Mg-Cu alloys with 8 wt.% Zn-2 wt.% Mg-2.3 wt.% Cu and 0.2 or 0.5 wt.% of Zr additions were investigated using X-ray diffraction measurements (XRD), scanning (SEM) and transmission electron microscopy (TEM) combined with energy dispersive X-ray (EDX) microanalysis. Rapidly solidified ribbons with thickness of 70-100 m were performed by melt spinning technique. The mould cast alloys as well as the melt spun ribbons revealed dendritic microstructure of (Al) solid solution and η Mg(Zn,Cu)2 phase in interdendritic areas. The refinement of the microstructure and reduction of the volume fraction of the η phase up to 1.7%, as compared to 4% in the mould cast alloys was observed in the ribbons. Copper dissolution up to about 20 wt % in the η phase causes a decrease of the lattice parameters. The Al3Zr primary precipitates were observed in the mould cast alloy containing 0.5 wt % of Zr while in the ribbons all zirconium dissolved in the aluminium solid solution.