Quantitative determination of crystalline and amorphous phase in traditional ceramics by combined Rietveld-RIR method

A mixture composed of quartz, clay minerals, and feldspars was heated at different temperatures in the range 1085-1215 degrees C for the production of traditional single firing white paste ceramics. The products display different physical and mechanical properties as a function of temperature. The variation of the physical properties such as the linear shrinkage,the water absorption, and others is directly related to changes in the phase composition and their microstructure, The quantitative determination of both crystalline (mullite, quartz, corundum, zircon, and albite) and amorphous phase (mainly alkali-aluminosilicatic glass), and the determination of some microstructural features of the phases have been calculated using the combined Rietveld-RIR method, a powerful X-Ray powder diffraction full profile fitting technique which was succesfully employed in a variety of applications (quantitative determination of asbestos in bulk materials, quantitative determination of the zeolite fraction and glass in pyroclastic tuffs, and others)