Nowe metody w badaniach struktur polikryształów

In this chapter, information on good laboratory practice in the field of structural powder diffractometry has been collected. The authors attempt to describe how to plan a measurement, how to find the cell parameters, how to build a model of the structure, and how to refine and verify it. There are many methods and procedures which lead to solving a crystal structure. However, the experience of recent years shows that, in the case of many materials, an investigator has to attempt the problem of structure solution using many different methods. The software is easily available (from ‘trial and error’ or classic to sophisticated modern approaches), as is a lot of good equipment. On the other hand, the complexity of the structures studied using powder diffraction methods is continually increasing. No description of any methods of research other than diffraction techniques is presented. We have also focused on polycrystalline materials. Amorphous substances and methods using the formalism of ‘pair distribution functions’ are beyond the scope of this paper. New methods of structural studies (including algorithms from research described in the literature, even if their applicability has been relatively slight) were treated with particular attention. In addition to the description of methods, we also collected some useful (in our opinion) information about available software and crystallographic databases.