Reduction reactions and densification during in situ TEM heating of iron oxide nanochains
Abstract
The reduction reactions and densification of nanochains assembled from γ-Fe2O3 nanoparticles were investigated using in situ transmission electron microscopy (TEM). Morphological changes and reduction of the metal oxide nanochains were observed during in situ TEM annealing through simultaneous imaging and quantitative analysis of the near-edge fine structures of Fe L2,3 absorption edges acquired by spatially resolved electron energy loss spectroscopy. A change in the oxidation states during annealing of the iron oxide nanochains was observed with phase transformations due to continuous reduction from Fe2O3 over Fe3O4, FeO to metallic Fe. Phase transitions during the in situ heating experiments were accompanied with morphological changes in the nanochains, specifically rough-to-smooth surface transitions below 500 °C, neck formation between adjacent particles around 500 °C, and subsequent neck growth. At higher temperatures, coalescence of FeO particles was observed, representing densification.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 21, 2017
- Source ID
- 10.1063/1.5004092
Entities
People
- Cecile S. Bonifacio
- Gautom Das
- Ian M. Kennedy
- Klaus van Benthem
Organizations
- Army Research Office
- National Institute of Environmental Health Sciences
- National Science Foundation
- University of California, Davis