Warren-Averbach procedure

Because large magnitudes of broadening were observed in PTFE, even for slowly cooled specimens, it was necessary to use line-width standards. The two materials used were annealed LiF and a diluted solid mixture of ammonium hydrogen phosphate. Data analysis proceeded by Fourier analysis of multiple orders, the well-known Warren-Averbach procedure. " Values of the domain size as measmed experimentally and with a correction using renormalized cosine coefficients (RCC), are given in Table 1.2. 

Ung4r T, Revesz A, Borbely A. Dislocations and grain size in electrodeposited nanocrystalUne Ni determined by the modified Williamson-HaU and Warren-Averbach procedures. J Appl Crystallogr 1998 31 554-558. 

The study of the peak shape gives important information relative to the microstructure of the sample even when it is included in the Rietveld code. Actually, in order to perform the Warren-Averbach analysis or other mi-crostructural studies, it is not necessary to use the Rietveld analysis, but it is often sufficient to operate with less complex, non-structural peak fitting procedures. 

The Warren-Averbach method starts from this consideration and takes into account the simultaneous presence of size and strain effects. Once the IP has been properly considered e.g. by a deconvolution procedure), the Fourier expansion of the intrinsic profile can be written as ... 

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