Strukturaufklärung in komplexen amorphen Systemen mittels Reverse-Monte-Carlo Simulationen

This work focusses on applying the Reverse-Monte-Carlo method for structure determination in complex amorphous materials using X-ray diffraction data. The complete data analysis starting with raw data corrections and finishing with the interpretation of results will be described on the basis of two different sample materials. Advantages and disadvantages of the Reverse-Monte-Carlo method are discussed and the need to critically judge structure models resulting from this method is highlighted. For the first material in question, which is a chalcogenide glass with the chemical composition Ga14.3Ge21.4Se64.3, the short range order is characterized. Most importantly, hints are found for a gallium-gallium correlation on a second-neighbour length scale which may be linked to the commercially relevant increase of rare-earth solubility in gallium containing glasses. The second material is an amorphous powder consisting of [(C6H5Sn)4S6] molecules. The molecular nature of this material poses difficulties for the structure determination and is the reason for Reverse-Monte-Carlo method development which was done in this project. As a result, first information regarding the relative positions of molecules could be gained and a strategy for further structure determination is suggested.