A rapid method for analysing the breadths of diffraction and spectral lines using the Voigt function

The Voigt function provides a rapid and easily applied method for interpreting the breadths of diffraction profiles in terms of specimen defects and for studying absorption or emission spectra. In the past, approximate methods have usually involved the assumption that the constituent profiles are either Cauchy (Lorentzian) or Gaussian, but a better representation of the experimental data is given by the convolution of these functions. The method is illustrated by analysis of the Cu Kαemission profile and of crystallite-size broadening in nickel powder.