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Imaging grain boundary grooves in hard-sphere colloidal bicrystals
Eric Maire1, Emily Redston1, Maria Persson Gulda1
1School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
Physical Review. E
|November 15, 2016
Summary
Researchers grew 3D bicrystals and studied atomic mobility at grain boundaries using confocal microscopy. Higher mobility was observed at grain boundaries and interfaces, revealing insights into material properties.
Area of Science:
- Materials Science
- Crystallography
- Colloid Science
Background:
- Controlled growth of three-dimensional (3D) bicrystals is essential for understanding material properties.
- Grain boundaries significantly influence material behavior and performance.
- Characterizing atomic mobility at interfaces is crucial for predicting material stability.
Purpose of the Study:
- To grow 3D bicrystals with controlled structures using colloidal particles.
- To investigate atomic mobility at different types of grain boundaries and solid-liquid interfaces.
- To quantify interfacial energies and compare them with theoretical estimates.
Main Methods:
- Sedimentation of colloidal particles onto patterned glass slides to form face-centered-cubic (FCC) bicrystals.
- Confocal microscopy for visualizing crystal structure and defects.
- Geometric measurements (image difference, thresholding, reprojection) to detect atomic mobility.
- Analysis of grooves at grain-boundary-liquid triple junctions.
Main Results:
- Successfully produced three types of symmetric tilt grain boundaries: Σ5(100), Σ17(100), and Σ3(110).
- Atomic mobility was found to be higher at grain boundaries and the solid-liquid interface.
- Grooves were observed at the grain-boundary-liquid triple junction for Σ5 and Σ17 boundaries, but not for the Σ3 twin boundary.
- Measured the angle relating grain boundary energy to solid-liquid interfacial energy.
Conclusions:
- Confocal microscopy with geometric analysis offers a straightforward method to detect atomic mobility in colloidal crystals.
- The presence and characteristics of grooves at triple junctions depend on the grain boundary type.
- Measured interfacial energies provide valuable data for validating theoretical models of grain boundary and solid-liquid interfacial energies.
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