Resonant X-ray scattering in the presence of several anisotropic anisotropic factors

The general form of the X-ray susceptibility tensor near absorption edges i s found when several anisotropic factors, such as the anisotropy of local a tomic environment. magnetic ordering and orbital ordering, simultaneously e xist in a crystal. Different phenomenological approaches are used to obtain the explicit form of the susceptibility tensor and to find the contributio ns from each anisotropic factor separately as well as 'combined' terms owin g to their simultaneous existence. The results of the theoretical treatment are applied to the resonant diffraction by La0.5Sr1.5MnO4 below the Neel t emperature, where charge and orbital ordering coexist with anisotropy of lo cal atomic environment. and magnetic ordering.