Papers by Keyword: Combined Analysis

Abstract: We illustrate the x-ray Combined Analysis approach capabilities in characterizing silicates and phyllosilicates for samples exhibiting crystallographic textures. Two mullite composite ceramics, one elaborated under uniaxial pressure the other under centrifugation, and one uniaxially pressed montmorillonite aggregate, are studied in terms of texture, cell parameters and phase contents. Several weak texture components are present in the mullite samples, combinations of planar- and fibre-like textures. The methodology is able to take account of the amorphous silica-like matrix of the composite, and cell parameters and structure of mullite correspond to the commonly modelled used for this phase. The montmorillonite turbostratic phase is correctly reproduced with its fibre texture, eventhough minor phases are also present and modelled in the aggregate.

Abstract: Orientation distributions of polyphased (Bi,Pb)2Sr2Ca2Cu3O10+d superconducting textured materials are determined from neutron diffraction analysis. The quantitative texture analysis of neutron data was accomplished by using the combined Rietveld-WIMV-Popa algorithms, implemented in the program package Materials Analysis Using Diffraction (MAUD). Curved position-sensitive detector and 4-circle diffractometry allow the whole diffraction pattern treatment. Transport critical current densities, measured on different samples, are strongly dependent of the calculated texture strengths, crystallite sizes and phase ratios. The results prove the interest of the combined approach for a quantitative texture analysis of complex materials. Texture to anisotropic physical properties relationship is discussed.