• core-void-shell;
  • stainless;
  • kirkendall;
  • core/alloy;
  • vacancy coalescence
Thumbnail image of graphical abstract

The oxidation properties of nanoparticles with core/alloy microstructure and stainless steel like interfaces is described. In particular, 15-nm Fe/FeCr nanoparticles with a stainless steel like interface are prepared. These particles show a unique morphological transformation that is induced by surface oxidation, oxide passivation, and vacancy coalescence. This Kirkendall diffusion results in a tailorable oxide layer thickness, Fe-core size, as well as void size and symmetry. Much like the interface of bulk stainless steel, the interfacial FeCr oxide passivates oxidation, resulting in self-limited diffusion. Because of this, a highly uniform and stable core-void-shell morphology is observed.