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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
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Spatially-varying inversion near grain boundaries in MgAl2O4 spinel
Blas P Uberuaga1, Romain Perriot2
1Materials Science and Technology Division, Los Alamos National Laboratory Los Alamos NM 87545 USA blas@lanl.gov.
RSC Advances
|May 2, 2022
Summary
Chemical inversion in complex materials is not uniform. A study on MgAl2O4 spinel reveals distinct inversion levels at grain boundaries compared to the bulk, impacting material properties.
Area of Science:
- Materials Science
- Solid-State Chemistry
- Crystallography
Background:
- Complex materials often display chemical disorder or inversion.
- This disorder is typically assumed to be spatially uniform throughout the material.
Purpose of the Study:
- To investigate the spatial distribution of chemical inversion in MgAl2O4 spinel.
- To understand the impact of microstructural features, specifically grain boundaries, on inversion levels.
- To correlate inversion characteristics with material energetics and defect interactions.
Main Methods:
- Analysis of a simple grain boundary in MgAl2O4 spinel.
- Modeling of inversion as a function of grain size.
- Extraction of inversion-relevant properties from experimental data.
Main Results:
- The level of inversion at the grain boundary plane differs from the bulk.
- Grain boundary inversion affects the energetics of the boundary and defect interactions, such as vacancy formation energy.
- A model demonstrates that experimentally prepared MgAl2O4 materials exhibit nearly fully inverse grain boundaries.
Conclusions:
- Microstructure, particularly grain boundaries, significantly influences chemical inversion in complex materials.
- The spatial heterogeneity of inversion must be considered for accurate material property prediction.
- Grain boundaries in MgAl2O4 spinel play a critical role in its overall inversion behavior.
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