THEORY OF SMALL-ANGLE X-RAY SCATTERING CAUSED BY INCOMPATIBILITIES IN ELASTIC ANISOTROPIC MEDIA AND THE APPLICATION TO DISLOCATIONS IN H.C.P. CRYSTALS

摘要

So, far. the Small-Angle X-Ray Scattering (SAXS) amplitude caused by internal stress sources which are described by an incompatibility field mas calculated for isotropic and cubic crystal symmetry by Kroner and Seeger. In this work this problem has been solved for arbitrary crystal symmetry within the framework of the linear anisotropic elasticity theory. Using the unique decomposition of the elastic strain tensor into the deformational and incompatible parts as an ansatz, the SAXS amplitude has been obtained by Fourier transformation of the basic equations of the internal stress theory. The integration problem can be reduced to the Fourier transformation of the incompatibility tensor only. A calculation of the volume dilatation field can be avoided in this way. The calculated SAXS amplitude is applied to dislocation loops in h.c.p. crystals. It is shown which information about these dislocation loops is available by measuring SAXS intensity contours. [References: 14]