Abstract
The oxidation of nickel particles was studied in situ in an environmental transmission electron microscope in 3.2 mbar of O2 between ambient temperature and 600°C. Several different transmission electron microscopy imaging techniques, electron diffraction and electron energy-loss spectroscopy were used to study the evolution of the microstructure and the local chemical composition of the particles during oxidation. Our results suggest that built-in field effects control the initial stages of oxidation, with randomly oriented NiO crystallites and internal voids then forming as a result of outward diffusion of Ni2+ along NiO grain boundaries, self-diffusion of Ni2+ ions and vacancies, growth of NiO grains and nucleation of voids at Ni/NiO interfaces. We also observed the formation of transverse cracks in a growing NiO film in situ in the electron microscope.
Original language | English |
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Journal | Acta Materialia |
Volume | 67 |
Pages (from-to) | 362-372 |
ISSN | 1359-6454 |
DOIs | |
Publication status | Published - 2014 |
Keywords
- In situ transmission electron microscopy (TEM)
- Electron energy-loss spectroscopy
- Oxidation
- Kinetics
- Diffusion