Multishell nanoparticles: Atomic‐Scale Characterization of Aluminum‐Based Multishell Nanoparticles Created by Solid‐State Synthesis (Small 16/2010)

Abstract

Core/double-shell nanoparticles are produced by solid-state precipitation in an aluminum matrix and characterized by atom-probe tomography (APT). By choosing three solute elements (Yb, Sc, Li) with substantially disparate diffusivities and by judiciously selecting aging temperatures to precipitate each element sequentially, nanoparticles are formed with three chemically distinct, concentric Al3(Yb,Sc,Li) regions with diameters of ∼3, 7, and 27 nm, respectively. An even more complex structure can be created when two such particles coalesce. The cover image shows an APT reconstruction of such a coalesced nanoparticle, reminiscent of a double-yolk egg. This novel structure consists of i) two Yb-rich Al3(Li,Yb,Sc) cores (“yolks,” rich in red Yb atoms) with 4--5 nm diameter, ii) two Sc-rich Al3(Li,Sc,Yb) inner shells (blue) surrounding their respective cores and iii) one Li-rich Al3Li outer shell (orange) enfolding the previous regions and contained within an Al matrix (black). For clarity, only the minority Yb atoms are shown. For more information, please read the Communication “Atomic-Scale Characterization of Aluminum-Based Multishell Nanoparticles Created by Solid-State Synthesis” by D. N. Seidman and co-workers, beginning on page 1728.