title: Size fluctuations of near critical nuclei and Gibbs free energy for nucleation of BDA on Cu(001).
abstract: We present a low-energy electron microscopy study of nucleation and growth of BDA on Cu(001) at low supersaturation. At sufficiently high coverage, a dilute BDA phase coexists with c(8×8) crystallites. The real-time microscopic information allows a direct visualization of near-critical nuclei, determination of the supersaturation and the line tension of the crystallites, and, thus, derivation of the Gibbs free energy for nucleation. The resulting critical nucleus size nicely agrees with the measured value. Nuclei up to 4-6 times larger still decay with finite probability, urging reconsideration of the classic perception of a critical nucleus.
authors.affiliation: Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, NL-7500AE Enschede, Netherlands.
authors.forename: Daniel
authors.initials: D
authors.lastname: Schwarz
authors.forename: Raoul
authors.initials: R
authors.lastname: van Gastel
authors.forename: Harold J W
authors.initials: HJ
authors.lastname: Zandvliet
authors.forename: Bene
authors.initials: B
authors.lastname: Poelsema