Stability of nanograins and nanoparticles in La-doped nanocrystalline steel irradiated with Fe ions

Nanostructured materials are potential candidates for future structural materials in advanced nuclear reactors. La-doped nanocrystalline 304 austenitic stainless steel (NC304-La) is an advanced nanostructured steel, in which excellent small grain size of ~45 nm is achieved and stabilized by the doped La element. We carried out irradiation using 3.3 MeV Fe ions to 108 dpa at room temperature and 500 °C, and then characterized the microstructural change in NC304-La by transmission electron microscopy, scanning transmission electron microscopy and atom probe tomography. We studied the detailed microstructural evolution and elemental behaviors in irradiated NC304-La, focusing on the effects of La element on the stability of nanograins and nanoparticles in NC304-La.