title: Pressure-induced evaporation dynamics of gold nanoparticles on oxide substrate.
abstract: Here we report thermal evaporation dynamics of Au nanoparticles on single crystal oxide substrates, including MgO, SrTiO(3), and Al(2)O(3). The size reduction rate of Au nanoparticles via thermal treatments is strongly dependent on not only temperature but also pressure. Lowering the pressure of inert Ar gas from 10(5) to 10 Pa increases the size reduction rate over 30 times in the temperature range 800 °C-950 °C. The temperature dependence is solely due to the variation of saturated vapor pressure of Au, whereas the pressure dependence of the surrounding inert gas can be interpreted in terms of a pressure dependence on a gas-phase diffusion of evaporated Au atoms into the surroundings. We present a simplified model to explain an evaporation dynamics, which well describes the pressure dependence on a size reduction rate of Au nanoparticles. By utilizing this useful pressure-induced evaporation dynamics, we succeeded in manipulating a size reduction of Au nanoparticle arrays down to -10 nm diameter range from -300 nm initial size by programming sequentially a surrounding pressure.
authors: The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka Ibaraki, Osaka, 567-0047, Japan.
authors: Gang
authors: G
authors: Meng
authors: Takeshi
authors: T
authors: Yanagida
authors: Masaki
authors: M
authors: Kanai
authors: Masaru
authors: M
authors: Suzuki
authors: Kazuki
authors: K
authors: Nagashima
authors: Bo
authors: B
authors: Xu
authors: Fuwei
authors: F
authors: Zhuge
authors: Annop
authors: A
authors: Klamchuen
authors: Yong
authors: Y
authors: He
authors: Sakon
authors: S
authors: Rahong
authors: Shoichi
authors: S
authors: Kai
authors: Tomoji
authors: T
authors: Kawai
mesh_terms: D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D005740:Gases / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D008956:Models, Chemical; D008958:Models, Molecular; D010087:Oxides / Q000737:chemistry*; D011312:Pressure
chemical_list: D005740:Gases; D010087:Oxides; D006046:Gold