Irradiation-induced formation of single-variant nanocrystals in an amorphous alloy

Physically isolated and crystallographically oriented single-variant nanocrystals (NCs) have been successfully formed in an Ni–P amorphous alloy using focused ion-beam (FIB) irradiation. The amorphous alloy was irradiated by the FIB at an incident ion beam angle of 35° to the specimen surface. Transmission electron microscopy observation has shown the formation of a large amount of NCs, approximately 20 nm in size, throughout the irradiated area. Electron diffraction analysis has revealed that the NCs have an fcc structure, with the irradiated-plane normal parallel to [111]fcc and the FIB direction parallel to [001]fcc, indicating that the NCs are single variant.