Yakovenko O. X-ray diffraction study of the Al-Ge-Fe(Ni) melts structure

The thesis is devoted to the study of the peculiarities of the atomic ordering of Al-Ge, Al-Ge-Fe (Ni) melts by means of X-ray diffraction and the Reverse Monte Carlo simulation. Analysis of the obtained data indicates a microinhomogeneous structure of Al-Ge melts near liquidus line due to the presence of fluctuation clusters with the structure of liquid germanium. It is shown that the structure of Al-Ge-Fe melts within the Fe70Ge30-Al65Ge30Fe5-Al90Ge10 region is microinhomogeneous due to the presence of clusters with the structure of liquid germanium, which is manifested on the structural factor curves in the form of inflow at the first maximum and decrease of the nearest interatomic distance. It is established that the presence of Ge atoms in the nearest environment of transition metal atoms is determined by the effect of competition between Al and Ge atoms. It was found that for Al-Ge-Ni melts the ability to amorphization is lower than for Al-Ge-Fe due to the stronger interaction in Al-TM and Ge-TM pairs, which promotes the formation of crystalline phases during cooling of the melt. In the Al-Ge-Fe system three new phases have been identified in the quenchеd by the melt-spun technique ribbons and in the ingot cast samples.