Dmitrienko Vladimir E, Ovchinnikova Elena N
A. V. Shubnikov Institute of Crystallography, 119333 Moscow, Russia.
J Synchrotron Radiat. 2003 Sep 1;10(Pt 5):376-9. doi: 10.1107/s0909049503011622. Epub 2003 Aug 28.
Point defects in crystals cause displacements of neighbouring atoms and hence become the source of an additional anisotropy of the X-ray resonant scattering amplitude. This anisotropy can induce 'forbidden' Bragg reflections near absorption edges, called point-defect-induced (PDI) reflections, which are absent in non-resonant X-ray scattering and in resonant X-ray scattering by perfect crystals. The deformation of external electron shells is the physical reason for this phenomenon. Some examples of crystals are considered in which the PDI reflections could be observed.
晶体中的点缺陷会导致相邻原子发生位移，从而成为X射线共振散射振幅额外各向异性的来源。这种各向异性会在吸收边附近诱发“禁戒”的布拉格反射，称为点缺陷诱导（PDI）反射，在非共振X射线散射和完美晶体的共振X射线散射中不存在这种反射。外部电子壳层的变形是这一现象的物理原因。本文考虑了一些可能观察到PDI反射的晶体实例。
