THEORY OF X-RAY DIFFRACTION ON CRYSTALLINE STRUCTURE WITH PARTICLES OF CYLINDRICAL SHAPE
V. Harutyunyan
Dept. of Solid State Physics, Yerevan State
University, A.Manukian 1, 375049 Yerevan, Armenia,
E-mail: valeryh@ysu.am
Keywords: texture, policrystalline material, strain
analysis, x-ray diffraction
There are wide range of materials, which consist of crystalline particles of cylindrical shape or contane such particles as a fraction. Therefore the problem of X-ray diffraction investigations of strains and particles sizes in such materials is of certain scientific interest.
In the present work the theory of monochromatic X-ray wave diffraction on crystalline structure of cylindrical particles is developed. The problem is considered both for plane and divergent X-ray wave. It is supposed that the functions of the particles distribution over the sizes and strains are Gaussian. The analytic expressions of intensity distribution for diffracted beam are obtained both for topographic and diffractometric methods of radiation recording. On the basis of these theoretical results a method, which enables to reconstruct the above-mentioned Gaussian distributions, is suggested.
The method suggested is applied to treat the experimental results obtained in our earlier work [1], which is devoted to investigations of strains in texture of calcium hydroxide crystallites with shape close to cylindrical.
The present theory is applicable to weakly expressed texture
as well as to policrystalline material.