Determination of the odd part of the texture function by anomalous scattering

Abstract

The texture function f(g) of a polycrystalline material may be split into two parts \tilde{f}(g) and \tilde{f}(g), where the first one contains the terms of even order l in the series expansion, whereas the second one consists of the odd-order terms. In the case of centrosymmetric crystals, or by virtue of Friedel's law in noncentrosymmetric crystals, the contribution of {\approx}\atop{f} to experimental pole figures is identically zero. Hence it is impossible to determine {\approx}\atop{f} from pole figures obtained by `normal' polycrystal diffraction experiments. It is suggested therefore that anomalous scattering of X-rays or neutrons should be used to determine {\approx}\atop{f} from pole figure measurements directly and the corresponding formulae are given.