Modeling of the Structural State of Amorphous Phases of the Nano-Sized Al2O3 Produced by Different Synthesis Methods

Resumo

The paper examines the structural state of the Al₂O₃ alloy nanopowders synthesized by different methods: electron beam evaporation, hydrolysis, and plasma-chemical method. X-ray structural analysis demonstrated that Al₂O₃ nanopowders synthesized by different methods are in X-ray amorphous and semi-amorphous states. These synthesis methods stimulate the creation of amorphous structures with different specific surfaces. The structural state of the Al₂O₃ alloy was studied by methods of X-ray structural analysis and simulation modeling. In order to identify the internal structure, modeling of the amorphous state of the elementary cell of the Al₂O₃ phase was performed within molecular dynamics. As a result of full-profile refinement of parameters of the model phases of Al₂O₃ nanopowders, complete structural information was identified for the synthesized Al₂O₃ alloys. It was shown from first principles that the cells of X-ray amorphous Al₂O₃ turned out to be highly stable. Researchers identified the parameters of elementary cells, spatial distribution of atoms, and node occupancy. It was shown that specific surface increases in the Al₂O₃ alloy nanopowders with the increase in bond energy of atoms in the cell.