Konotop O. Features of structure and composition of free two-component clusters based on rare gases

The dissertation presents the experimental results of transmission electron diffraction studies of structure, microstructure, and mechanisms of composition formation of substrate-free heterogeneous clusters formed in the process of adiabatic expansion of Ar-Kr, Kr-Xe, and N2-Ar gas mixtures into a vacuum through a supersonic nozzle. The impact of the thermodynamic properties and composition of primary gas mixtures on heterogeneous nucleation in the jet, cluster size and its enrichment with the heavier component is studied. Semi-empirical relations are obtained which allow one to effectively manage the size and composition of clusters formed in binary supersonic jets. The transmission from the fcc structure to a two-phase fcc-hcp one in rare-gas clusters is investigated. It is found that the relative volume of the hcp phase in heterogeneous Ar-Kr aggregations is much greater than that in homogeneous Ar and Kr clusters of the same size. A correlation between the number of deformation-induced stacking faults in clusters and the phase composition of clusters when their size is changed is established and a model of the hcp-phase nucleation and growth in substrate-free rare-gas clusters is proposed.