Iron-atom condensation interpreted by a kinetic model and a nucleation model approach

Homogeneous nucleation of iron from supersaturated vapor investigated by molecular dynamics simulation

“…For the high supersaturation investigated here one would obtain cluster sizes smaller than a monomer which makes it difficult to use a macroscopic surface tension. This agrees with the observations of Giesen et al (2004) who could apply classical nucleation theory only for lower supersaturation using a size-dependent surface tension. Similarly, in case of nucleation of silver the critical cluster size has been estimated in the order of 0.9-1.9 atoms in an experimental investigation (Nuth, Donnelly, Donn, & Lilleleht, 1986).…”

“…6a the resulting nucleation rates are compared to the data recently published by Giesen et al (2004). The data are correlated with Eq.…”

“…For the experimental investigation of metal vapor nucleation different methods are required. A supersaturated metal vapor can be generated by decomposition of a precursor gas (Freund & Bauer, 1977;Giesen, Kowalik, & Roth, 2004). In case of iron this can be iron pentacarbonyl which is in a thermodynamically stable gas phase at given conditions.…”

Overview: Homogeneous nucleation from the vapor phase—The experimental science

“…Alternatively, the shock wave moving though the low pressure section (LPS) can raise the temperature enough to induce a chemical reaction in a volatile species that is then followed by nucleation of the non-volatile product. 86 Peters, 159 and later van Dongen and co-workers, 160,161 incorporated features into the driven section to modify the expansion and create a well-defined, ∼1 ms long, nucleation pulse as illustrated in Fig. 5.…”

“…We will not address heterogeneous nucleation, [44][45][46] and only address ion induced nucleation 47,48 and nucleation driven by chemical reactions in the context of atmospheric new particle formation. It is not possible to discuss all the experimental systems of interest 49 that range from simple gases [50][51][52][53][54][55][56] (Ar, N 2 , and CO 2 ) through organics of increasing complexity (alkanes and alcohols), and even metals [82][83][84][85][86] (Na, Mg, Fe). Rather, we will illustrate the progress in experimental nucleation research primarily using the results for water and aqueous systems both because of the critical role water nucleation plays in industry and in the environment, and because the data set is incredibly rich.…”