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Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Apparent mismatch between extended x-ray absorption fine structure and diffraction structures of crystalline
J Moscovici1, A Rougier, S Laruelle
1Laboratoire de Physique Structurale des Molécules et Matériaux, Faculté des Sciences et Technologie, Université Paris 12, 61 Avenue du Général de Gaulle, 94010 Créteil Cedex, France. moscovic@univ-paris12.fr
The Journal of Chemical Physics
|October 4, 2006
Summary
Extended x-ray absorption fine structure spectroscopy revealed local structural disorder and vacancies in tungsten trioxide (WO3) phases. These findings are crucial for understanding amorphous and thin film WO3 electrochromic materials.
Area of Science:
- Materials Science
- Solid State Chemistry
- Spectroscopy
Background:
- Tungsten trioxide (WO3) is a key material in electrochromic devices.
- Understanding the local structure of WO3 is essential for optimizing its performance.
- Previous studies often assumed ideal crystal structures.
Purpose of the Study:
- To investigate the local atomic structure of various WO3 phases.
- To analyze model compounds relevant to amorphous and thin-film WO3 electrochromics.
- To reconcile experimental findings with existing crystallographic data.
Main Methods:
- Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy.
- Analysis of monoclinic, monohydrate, hexagonal, and pyrochlore WO3 phases.
- Comparison with published crystal structure data.
Main Results:
- A broad distribution of W-O bond distances (1.70–2.35 Å) was observed in all studied WO3 phases.
- The experimental results deviate from previously reported crystal structures.
- Discrepancies are attributed to the presence of vacancies and local distortions.
Conclusions:
- The local structure of WO3 is characterized by significant disorder.
- Vacancies and local distortions play a critical role in the structure of WO3.
- These findings provide insights into the behavior of WO3-based electrochromic materials.
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