Nanoscale physics

Redistribution of atomic components in Ni-Al Janus-like nanoclusters under the interaction with argon clusters
Shyrokorad D.V., Kornich G.V.
Department of system analysis and computational mathematics, Zaporizhzhia National Technical University. Zhukovskogo st., 64, Zaporizhzhia -69063, Ukraine. 
E-mail: hoveringphoenix@gmail.com

Nickel-based materials are of great importance in advanced technologies, such as structural elements in gas and hydro turbines, turbocompressor rotors, high-temperature dies and molds, supercapacitors, cutting tools, etc. In the nanoscale range, Ni-Al is an important material for nanocatalysts [1,2].
Within the framework of classical molecular dynamics, the possibility of controlled modification of the initial Janus-like Ni-Al nanoclusters consisted of 390 atoms by the impacts of argon clusters of various sizes and energy in the range of 0.1 – 1.0 keV to create bicomponent nanoparticles of the desired structure and composition, is considered.
The negative heat of mixing of nickel and aluminum leads to active mixing of the components and the formation of a practically homogeneous bimetallic cluster already at low bombardment energies. However, detailed investigation of the resulted nanostructures, including layered analysis, calculation of the radii of the mono-component parts, and intercenter distances, showed pronounced aluminum enrichment of the outer layer. The reasons of these processes were larger lattice constant and as result larger effective atomic size as well as lower cohesive energy of Al against Ni. This tendency is observed both for the cases of Ar1 and Ar13 bombardment, but larger projectile led to the intensive preferential sputtering and evaporation of Al atoms on the background of high temperature. Thereby, the variation of the size and the energy of the bombarding particles can readjust the macro-structural parameters of the resulted bimetallic nanoclusters to the magnitudes that are needed to the particular application.

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