Core/shell structural transformation and brittle-to-ductile transition in nanowires

摘要: Nanowires (NWs) exhibit thermo-mechanical properties that are distinct from their bulk properties, and understanding is critical for the reliability, manufacturability, optimization of a wide range devices consisting NWs. Here, molecular-dynamics simulation reveals rich size-temperature “phase diagram” mechanical response zinc-oxide NW under tension. For smaller diameters higher temperatures, transitions found brittle cleavage to structural transformation-mediated ductile failure. Atomistic mechanisms unique nano-thermo-mechanical behavior elucidated as consequence surface-structural relaxation, which in particular predicts spontaneous formation core/shell structure The phase diagram resolves controversies between previous experiments theory, predicted “intrinsic” may find device applications.