Normalization and Absorption Correction of Arbitrary X-Ray Scattering Intensities of Paracrystalline Substances

Abstract

A method has been developed for normalization and absorption correction of x-ray scattering intensities of paracrystalline substances, i.e., matter in a state intermediate between crystalline and amorphous states. In the method, the equation for the observed intensities is transformed into a linear form, φ(s, μT)=K[1+g(s, μT)]+Ki(s), where i(s) is the oscillatory part of the interference function. If a proper value is assigned to μT, a plot of φ vs g yields a straight line (having a slope K) modified only by the oscillations of i. When MoKα radiation is used, the period of such oscillations becomes small compared to the range of g. The mean value of i is zero in the medium- and high-angle range; therefore, a straight-line correlation of φ with g to yield a slope having a value equal to that of the intercept allows the determination of μT and K with an accuracy within the precision of measurement of the scattered intensities. The method is readily programmed for a computer.