Self-assembled nanoparticle spirals from two-dimensional compositional banding in thin films

Dinesh K. Venkatachalam, Neville H. Fletcher, Dinesh K. Sood, Robert G. Elliman

    Research output: Contribution to journalArticlepeer-review

    6 Citations (Scopus)

    Abstract

    A self-assembly process is reported in which spiral patterns of gold nanoparticles form on silicon surfaces during the epitaxial crystallization of thin gold-silicon alloy layers. This behavior is observed only for gold concentrations above a critical value and is shown to result from two-dimensional compositional banding of a liquid alloy layer during the crystallization process. The compositional banding consists of alternate gold-rich and silicon-rich alloy bands, which are shown to be a direct consequence of free energy minimization, the band spacing being that which gives the maximum diffusive composition-separation rate. Gold nanoparticles subsequently form by Ostwald ripening on the surface of the gold-rich bands to give rise to the observed spiral patterns.

    Original languageEnglish
    Article number213110
    JournalApplied Physics Letters
    Volume94
    Issue number21
    DOIs
    Publication statusPublished - 2009

    Fingerprint

    Dive into the research topics of 'Self-assembled nanoparticle spirals from two-dimensional compositional banding in thin films'. Together they form a unique fingerprint.

    Cite this