Unit cell refinement of Montmorillonite clay using the Rietveld method

Clays such as Montmorillonite present a unique challenge in unit cell and structure refinement due to their layered structures. The semi - crystalline nature of these materials, stemming from the disorder associated with the layered structures, gives rise to broadly asymmetric peak profiles that can be difficult to interpret.

Figure 1 shows a powder diffraction pattern collected on the Ultima IV multipurpose diffraction system for Montmorillonite clay together with a matching card of the phase from the ICDD database. Figure 2 shows the results of a Rietveld refinement of the material using a model obtained from the ICDD phases.

Powder diffraction pattern
Figure 1

Powder diffraction pattern
Figure 2



The Ultima IV represents the state-of-the-art in multipurpose X-ray diffraction (XRD) systems. Incorporating Rigaku's patented cross beam optics (CBO) technology for permanently mounted, permanently aligned and user-selectable parallel and focusing geometries, the Ultima IV X-ray diffractometer can perform many different measurements...fast. Read more...

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