Structure and properties of supersaturated Ni-Au nanoparticles revealed by GRK researchers

Symbolic picture for the article. The link opens the image in a large view.

In a joint effort across 4 GRK subprojects involving 10 GRK members, CENEM’s strength of combining different (scattering) probes revealed fascinating structural, chemical as well as mechanical properties of supersaturated and highly faceted Ni-Au nanoparticles equilibrated by solid-state dewetting on sapphire.

The results, which were recently published in Acta Materialia (https://doi.org/10.1016/j.actamat.2021.117318), include the impact of Au on the faceting, and the structural, morphological as well as chemical evolution of the nanoparticles over a wide spread of Au concentrations. In this context, Au segregation at the particle-substrate interface complemented by misfit dislocation in stand-off position could be identified and further discussed within an empirical model. Besides altering the interface structure, Au alters the mechanical properties of the equilibrated nanoparticles from an intermittent and discrete plastic flow behavior into a homogeneous deformation regime at large compressive strain.