New Developments in Microstructure Analysis via Rietveld Refinement

Innovative applications of the Rietveld method [1-3] are likely to include new developments in microstructure analysis. More and more samples show microstructure effects on line profile shape, width and position. Reasons are obviously the powder diffractometer resolution improvements at leading synchrotron sources, and the increasing user number. When the minimal full width at half maximum is as low as 0.01° (2θ) (synchrotron data), sample effects are no longer occulted by instrumental effects. Finer microstructure details are revealed, needing adapted Rietveld software. Previous reviews on this topic have reported methods used to model anisotropic size and microstrain broadening in the Rietveld method [4-7]. A more general survey will be available in the forthcoming book Microstructure analysis by Diffraction (H.-J. Bunge, J. Fiala and R.L. Snyder, Eds.). Recent innovations/applications are discussed in this paper, with a special emphasize on anisotropic effects in the Rietveld method.