On the intrinsic hook effect associated with pseudo-Voigt profiles

An intrinsic hook effect was always found to be associated with pseudo-Voigt (p-V) profiles when eta was less than 0.328 and the FWHM was small (similar to0.02degrees), where eta is the fraction of the Cauchy component and FWHM is the full width at half-maximum. The applicability of the Warren-Averbach (WA) analysis for the case of p-V profiles was thoroughly studied and it was found that a p-V profile with eta values ranging from 0 to 1 can be safely subjected to WA analysis, provided that the FWHM of the profile is large enough (2w similar or equal to 0.378degrees).