Single-crystal X-ray diffractometry using synchrotron radiation

The high brilliance over a wide spectral range up into the hard X-ray region, the small source size and low divergence, the polarization properties and the pulsed time structure are outstanding properties of synchrotron radiation that extend the range of single-crystal X-ray diffractometry to experiments which are not feasable with conventional sources, such as sealed X-ray tube or rotating anode equipments. There is almost no field of X-ray diffraction that cannot profit from the use of synchrotron radiation. Data collection techniques depend on the general goals of a diffraction experiment, but also on source and beamline optics, on the sample quality, its absorption and scattering power, as well as on the instrumental resolution function and the resulting reflection profile shape. Often, the sample properties play a crucial role, and not all samples may be suitable for data collection with synchrotron X-rays. The high intensity requires detectors with high count-rate capabilities; area detectors are highly desirable for high-speed data collection and maximum throughput. The time dependence of the primary beam intensity and of its polarization state requires monitoring and normalization to monitor counts, which complicates data collection and data reduction due to source of both random and systematic errors not encountered in conventional X-ray sources. X-ray diffraction with synchrotron radiation can yield structure factors of unprecedented quality, provided proper attention is given to sample properties, data collection strategy and data evaluation procedures. Synchrotron radiation does not, however, provide a solution to all problems, in some cases laboratory X-ray sources may be more appropriate. Given the limited access to synchrotron radiation facilities, X-ray diffraction with synchrotron radiation can only supplement, but not replace conventional X-ray sources and diffraction techniques