Quantitative Determination of Preferred Orientation

摘要

Solutions are presented to the problems which usually prevent accurate x-ray determinations of preferred orientation. The relationship between observed and corrected intensities and the angle dependent absorption factors are treated, including the case of displaced and distorted line profiles caused by low absorption in thick specimens. The absorption factors are derived experimentally from measurements of the scattered (Compton) background radiation without recourse to calculations or tables. Two simple methods, either by varying the wavelength λ or the order n of the x-ray reflection, span the region of the pole figure in which data are unreliable or unobtainable if only one wavelength or order is used. Random samples are not required for normalizing the data to ``times random'''' units. The intensity for a random sample can be calculated from the corrected data itself and the equation Ihkl=[[double integral operator]Ihkl(α,β) sinαdαdβ]/2π where (α,β) are the coordinates of a point on the usual polar net. It is suggested that textures can generally be represented by Gaussian or superposition of Gaussian orientation distributions.