title: Approach and Coalescence of Gold Nanoparticles Driven by Surface Thermodynamic Fluctuations and Atomic Interaction Forces.
abstract: The approach and coalescence behavior of gold nanoparticles on a silicon surface were investigated by experiments and molecular dynamics simulations. By analyzing the behavior of the atoms in the nanoparticles in the simulations, it was found that the atoms in a single isolated nanoparticle randomly fluctuated and that the surface atoms showed greater fluctuation. The fluctuation increased as the temperature increased. When there were two or more neighboring nanoparticles, the fluctuating surface atoms of the nanoparticles "flowed" toward the neighboring nanoparticle because of atomic interaction forces between the nanoparticles. With the surface atoms "flowing", the gold nanoparticles approached and finally coalesced. The simulation results were in good agreement with the experimental results. It can be concluded that surface thermodynamic fluctuations and atomic interaction forces are the causes of the approach and coalescence behavior of the gold nanoparticles.
authors.affiliation: State Key Laboratory of Tribology, Tsinghua University , Beijing 100084, China.
authors.forename: Jiadao
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Tribology, Tsinghua University , Beijing 100084, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Tribology, Tsinghua University , Beijing 100084, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Tribology, Tsinghua University , Beijing 100084, China.
authors.forename: Dangguo
authors.initials: D
authors.lastname: Li
authors.affiliation: State Key Laboratory of Tribology, Tsinghua University , Beijing 100084, China.
authors.forename: Darong
authors.initials: D
authors.lastname: Chen
keywords: approach; atomic interaction force; coalescence; nanoparticles; surface thermodynamic fluctuation