Blind lattice-parameter determination of cubic and tetragonal phases with high accuracy using a single EBSD pattern.

Area of Science:

• Materials Science
• Crystallography
• Analytical Chemistry

Background:

• Accurate crystallographic characterization is crucial for understanding material properties.
• Electron Backscatter Diffraction (EBSD) is a powerful technique for analyzing crystal structures.
• Determining lattice parameters and Bravais lattices of unknown materials can be challenging.

Purpose of the Study:

• To develop and validate a blind method for determining Bravais lattices and lattice parameters using EBSD patterns.
• To assess the accuracy and reliability of the EBSD technique for crystallographic characterization.
• To investigate the influence of pattern quality on the accuracy of lattice parameter determination.

Main Methods:

• Utilizing electron backscatter diffraction (EBSD) patterns from materials with cubic or tetragonal crystal structures.
• Employing a blind determination approach for Bravais lattices and lattice parameters.
• Analyzing geometric relationships within EBSD patterns to calculate lattice parameters and axial ratios.
• Comparing results from simulated and experimental EBSD patterns.

Main Results:

• Lattice parameters and axial ratios were determined with high accuracy (relative errors of ~0.7% and ~0.07%, respectively) for simulated patterns.
• Crystal orientation determination accuracy reached ~0.06°.
• Experimental patterns yielded slightly lower accuracy than simulated ones due to lower quality and systematic errors.
• Manual band detection improved the accuracy of lattice parameter determination from experimental patterns.

Conclusions:

• The developed EBSD-based procedure provides a reliable method for the blind crystallographic characterization of Bravais lattices.
• The technique is particularly effective for materials with cubic and tetragonal crystal structures.
• Accurate detection of diffracting-plane traces and zone axes is key to the method's success.