X-Ray Diffraction Study of Micro Amounts of Polycrystalline Samples

With the use of reference polycrystalline 6h-Al2O3 (NIST SRM- 1976) and MoO3 samples we consider the most significant geometric and physical factors affecting the accuracy of X-ray diffraction data obtained on a diffractometer equipped with a flat two-dimensional detector (Debye-Scherrer scheme). A general strategy to measure polycrystalline samples in the amount of 20–30 fug is proposed. By the example of SRM-1976 it is shown that with the proper processing of two-dimensional diffraction patterns and the introduction of certain corrections the angles 2θ can be measured with the accuracy not less than ±0.01°. Even with a strong tendency of particles towards preferred orientation the relative intensities of diffraction reflections are shown to be obtained with the accuracy not less than ±10%.