Optimizing electron backscatter diffraction of carbonate biominerals-resin type and carbon coating

Area of Science:

• Materials Science
• Geology
• Biomineralization

Background:

• Electron backscatter diffraction (EBSD) is increasingly used for crystallographic analysis of biogenic carbonates.
• Limited guidance exists on optimal sample preparation techniques for these materials.

Purpose of the Study:

• To investigate the impact of different sample preparation methods on EBSD data quality in biogenic carbonates.
• To determine the optimal resin embedding and carbon coating thickness for EBSD analysis of insulators.

Main Methods:

• Biogenic aragonite and calcite from Mytilus edulis were embedded in various resins (including epoxy).
• Samples were coated with thin layers of carbon (2.5 nm and 5 nm).
• EBSD data quality was assessed based on diffraction intensity and charging effects.

Main Results:

• Epoxy resin embedding significantly improved EBSD results for carbonate biomineral samples.
• A 2.5 nm carbon coating provided sufficient conductivity for EBSD analysis without obscuring the signal.
• Thicker carbon coatings (≥5 nm) reduced diffraction intensity.

Conclusions:

• Optimized sample preparation, specifically resin embedding and precise carbon coating thickness, is vital for high-quality EBSD analysis of biogenic carbonates.
• This study provides essential protocols for researchers analyzing crystallographic orientations in insulating biominerals.