X-ray Rietveld refinement using Debye-Scherrer geometry

A procedure for Rietveld refinement from Debye-Scherrer X-ray diffraction patterns is described, in which the effects of instrumental aberrations on the peak shapes and positions are calculated and incorporated into the refinement model. These aberrations, neglected in previous Rietveld refinement programs, can produce severe systematic errors in both the structural and non-structural parameters derived. Results presented from four materials (SiO₂, AlPO₄, Al₂O₃, LiTaO₃) are in good agreement with single-crystal values and are an improvement over those previously obtained by X-ray powder diffraction.