INTRODUCTION
All lattice imperfections, including finite sizes and strains/stress of grains or crystallites of the material, give rise to
broadening of X-ray diffracted-line profiles.
The application of powder diffraction techniques for the determination of micro-strains of imperfect materials dated
from 1940 when the pioneering work showed that the desired function of strain distribution can be obtained from the
measurable functions of intensities by making use of Fourier series method. Luland reported the breadths of several
curves of interest in the diffractometry. However, the earliest functions to be used and ones still widely employed in
this field were Cauchy and Gaussian. In these cases, function was necessarily a good approximation to broaden line
and there was evidence that a better representation can be obtained from the convolution of one or more Cauchy and
Gaussian functions.....
