The bio-imaging and diffraction beamline P11 at PETRA III

Abstract

The safety and quality of products made from different materials depend on the quality of metrological assurance used for characterization of the composition and properties of these materials. Modern diffractometric systems have new components which increase the productivity of these systems, whereas they may cause new uncertainties in the results of determining of the characteristics based on the diffraction pattern measurement data. Therefore of the considerable changes are needed in the Testing Program for Type Approval. Note that some manufacturers and users may not pay due attention to the metrological assurance, and the reliability and repeatability of characteristics. Some types of diffractometers are tested only for one and unconventional characteristic of the diffraction pattern, for example, angular position at small angles of diffraction reflections. As results is allows provide assurance for approximate phase analysis only. The accuracy for the positions of these reflections can be lower by one order of value than for the reflections whose positions are at very high values of angles, but it is based on these values that the uncertainty of crystal lattice parameters is determined just. In order to provide a more profound and overall testing of diffractometers for Russian Federation have been developed a new programs and certified measurement procedures and the system of Certified Standard Reference Materials (CSRM) of diffraction properties, based on stable physical characteristics and related to the parameters of the diffraction pattern [1-2]. Note that the results of comparative measurements show that the achieved accuracies for our CSRM and for the similar SRM systems available at NIST are alike. This CSRM system allows to conduct tests of X-ray diffractometers for conventional and new purposes: 1) a quantitative phase analysis based on the ratio of reflection intensities and on the results of measuring of a complete diffraction pattern using the Rietveld methods; 2) determining of micro-structural characteristics (grain sizes, sizes of nano-fragments and the value of micro-distortions of a crystal lattice) which are in demand especially in the machine-building, microelectronics and bio-nanotechnology. For this purpose we use CSRM and Measures with different levels of micro-distortions and taking into account the atomic weights of components; 3) determining of the life-service of a product on the basis of residual stress. The use is made of tablet-shaped, sintered CSRMs and measures; 4) for single crystal diffractometers we have developed new relevant and required CSRMs also.