Ing. Jan Rohlíček, Ph.D.
The laboratory of X-ray powder diffraction at the Department of Structure Analysis is equipped with two modern X-ray diffractometers which allow a wide range of measurements for phase analysis, for study of phase changes at different temperatures, for structure analysis or for thin film analysis.
The main activity of the laboratory is the so-called structural analysis. The fundamental problem of the structural analysis on powder samples is the solution of the so-called phase problem, i.e. the determination of the approximate structural model. In this area we use the Superflip program, which was developed in our department, or the FOX program, in which our department was partially involved. Both programs use a substantially different approach to structure solution process. The last phase of the structural analysis is the refinement of atomic parameters by the so-called Rietveld method. Rietveld refinement is carried out using the crystallographic computing system Jana, which is also being developed in our department. Another activity of the laboratory is the study of phase changes at different temperatures and the study of the reaction kinetic of substances in the flow or reaction capillary. The laboratory equipment allows the study of samples in the temperature range from 90 K to 1450 K. Study of solid state reactions can be studied due to the developed holder in which the reaction capillary is placed. Laboratory equipment allows also studying the properties of thin films. In the laboratory it is possible to measure the reflectivity to determine the layer thickness from 1 to 300 µm and rocking curve or reciprocal space mapping to determine the orientation and quality of the thin layer.
