Analysis of X-ray Diffraction Line Broadening using a Non-ideal Standard Specimen

Abstract

Abstract In practice a standard specimen used for the elimination of instrumental broadening, by deconvolution, is never ideal. The instrumental line profile always contains some additional broadening due to finite particle size and distortion present in the standard specimen. Further it is sometimes unavoidable to use a standard specimen of a material different from the material to be analyzed, leading to reflections at incorrect sin θ-values (different spectral broadening). Firstly the effect of these deficiencies on the Fourier coefficients of the pure line profile is analyzed. Secondly the consequences for size-strain analysis are considered. A correction [Eq. (3.4) ] for the difference in spectral broadening between the exact and the approximate instrumental line profile is given. To avoid serious errors, this correction should be performed before particle size and strain are determined according to the so-called Warren- Averbach analysis. Accurate relative determinations of size and strain are possible even in the case that the line profile under investigation and the line profile of the reference specimen are at different sin θ-values. It is suggested that standard specimens which cause noticeable structural broadening can be used profitably.