Exploring Pore Formation of Atomic Layer-Deposited Overlayers by in Situ Small- and Wide-Angle X-ray Scattering
| Autor: | Tao Li, Randall E. Winans, Christian P. Canlas, Jeffrey W. Elam, Yang Ren, Haiyan Zhao, Bachir Aoun, Saurabh Karwal |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
Small-angle X-ray scattering Annealing (metallurgy) General Chemical Engineering Nanoparticle 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Amorphous solid Crystallography Atomic layer deposition Chemical engineering Materials Chemistry Thin film 0210 nano-technology Porosity Wide-angle X-ray scattering |
| Zdroj: | Chemistry of Materials. 28:7082-7087 |
| ISSN: | 1520-5002 0897-4756 |
| Popis: | In this work, we explore the pore structure of overcoated materials by in situ synchrotron small-angle (SAXS) and wide-angle X-ray scattering (WAXS). Thin films of aluminum oxide (Al2O3) and titanium dioxide (TiO2) with thicknesses of 4.9 and 2.5 nm, respectively, are prepared by atomic layer deposition (ALD) on nonporous nanoparticles. In situ X-ray measurements reveal that porosity is induced in the ALD films by annealing the samples at high temperatures. Moreover, this pore formation can be attributed to densification resulting from an amorphous to crystalline phase transition of the ALD films as confirmed by high-resolution X-ray diffraction and the pair distribution function. Simultaneous SAXS and WAXS results show not only that the porosity is formed by the phase transition but also that the pore size increases with temperature. |
| Databáze: | OpenAIRE |
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