PMC

All atomic shells of both a QNb and b QMo show signs of the Invar effect through a change of slope at the dilatometric transition temperature. This effect is particularly strong in the first atomic shell and gets stronger after relaxation. The higher-order peak positions are shifted for clarity. The same nominal increase of atomic distances becomes proportionally less significant at higher-order atomic shells; the relative changes of average atomic distances are thus scaled for better readability. The insets show the heating and cooling runs for the first atomic shell, where the heating runs differ from each other due to structural relaxation at the end of the first heating.

Evolution of radius of Au atoms (a) and Ni atoms (b) during heating process, (c) Volume change versus Au/Ni atomic ratio (d) MSD of NP1-NP8.

The first atomic shell of QNb consists of a Fe–Y,Nb and b Fe–Fe in QNb. In QMo, the first atomic shell is comprised of c Fe–Y,Mo and d Fe–Fe. The average Fe–Fe distance is reduced at the dilatometric transition temperature (marked with arrows) and a change in the contraction rate is clearly visible. This effect is stronger after the sample has been heated close to the glass transition temperature in the first heating run. After heat treatment also the Fe–Y,Nb and Fe–Y,Mo atomic pairs show a change in the expansion rate at the dilatometric transition temperature.

Evolution processes of nanocubes into the concaved shape via (a) a traditional growth approach with atomic adsorption on selected facets (b) an approach in this work with atomic desorption on selected facets.