Diffusion and nucleation in multilayer growth of PTCDI-C8 studied with in situ X-ray growth oscillations and real-time small angle X-ray scattering
| Autor: | Anton Zykov, Jürgen P. Rabe, Sebastian Bommel, C. Weber, Paul Beyer, Christopher Wolf, Gonzalo Santoro, Stefan Kowarik, Linus Pithan |
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| Přispěvatelé: | German Research Foundation |
| Rok vydání: | 2017 |
| Předmět: |
Surface diffusion
Diffusion barrier Chemistry Small-angle X-ray scattering Scattering Nucleation General Physics and Astronomy 02 engineering and technology 021001 nanoscience & nanotechnology Thermal diffusivity 01 natural sciences Molecular physics Crystallography ddc:540 0103 physical sciences Diffusion-limited aggregation Physical and Theoretical Chemistry Diffusion (business) 010306 general physics 0210 nano-technology |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname The journal of chemical physics 146(5), 052803-(2017). doi:10.1063/1.4961460 |
| Popis: | The journal of chemical physics 146(5), 052803 - (2017). doi:10.1063/1.4961460 We study nucleation and multilayer growth of the perylene derivative PTCDI-C$_8$ and find a persistent layer-by-layer growth, transformation of island shapes, and an enhancement of molecular diffusivity in upper monolayers (MLs). These findings result from the evaluation of the ML-dependent island densities, obtained by in situ real-time grazing incidence small angle X-ray scattering measurements and simultaneous X-ray growth oscillations. Complementary ex situ atomic force microscopy snapshots of different growth stages agree quantitatively with both X-ray techniques. The rate and temperature-dependent island density is analyzed using different mean-field nucleation models. Both a diffusion limited aggregation and an attachment limited aggregation model yield in the first two MLs the same critical nucleus size i, similar surface diffusion attempt frequencies in the 10$^{19}$-10$^{20}$ s$^{−1}$ range, and a decrease of the diffusion barrier E$_d$ in the 2nd ML by 140 meV. Published by American Institute of Physics, Melville, NY |
| Databáze: | OpenAIRE |
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