Modelling of the influence of nanostructures' sizes on lattice parameters

TL;DR

This paper uses computer modeling to study how the sizes of nanostructures influence their atomic arrangements and lattice parameters, revealing increased disorder at boundaries as sizes decrease.

Contribution

It introduces a detailed atomistic modeling approach to analyze size-dependent lattice parameter variations in nanostructures, including bi-atomic molecules.

Findings

Atoms on boundaries are more loosely packed than in the volume.

Smaller nanostructures exhibit increased atomic and molecular disorder.

Larger nanostructures have more ordered lattices in the volume than at boundaries.

Abstract

Computer modeling of formation of the one-dimensional and three-dimensional monatomic nanostructures by the method of atom-atom potentials was done. The arrangement of atoms was defined on the basis of the energy minimum. Our calculations have shown that the distance between the nearest atoms depends on number of atoms, thus atoms on boundary of grains of nanoparticles have more loose packing than in the volume. In three-dimensional nanostructures at reduction of their sizes increase of the disorder of atoms on positions is observed. Examination of model nanostructures constructed of bi-atomic molecules was also carried out. It is shown that distance between the nearest molecules and their orientation depend on number of molecules surrounding them. Molecules on boundary of grains of nanoparticles have more friable packing than in the volume. As in the linear chain, and three-dimensional nanostructures constructed of bi-atomic molecules, not only the disorder on positions of molecules depending on the sizes of nanoparticles, but also the orientation disorder is observed. At increase of the sizes of nanostructures the lattice in volume becomes more ordered than on boundaries of nanoparticles grains.