Solving the Crystal Architecture of Coccoliths Using 4D-STEM.

Area of Science:

• Biomineralization
• Marine Biology
• Materials Science

Background:

• Marine phytoplankton, particularly coccolithophores, produce intricate calcite biominerals known as coccoliths.
• Coccolith morphology varies by species, but crystals are systematically arranged around an organic matrix, exhibiting high symmetry.

Purpose of the Study:

• To demonstrate the capabilities of four-dimensional scanning transmission electron microscopy (4D-STEM) for spatially resolving the crystallography of marine biominerals.
• To develop a computational pipeline for automated crystal orientation mapping within complex biomineral structures.

Main Methods:

• Utilizing four-dimensional scanning transmission electron microscopy (4D-STEM) for parallel real-space and diffraction-space recordings.
• Developing a computational pipeline to automatically determine crystal orientation at the pixel level.

Main Results:

• Successfully mapped the orientation of entangled and overlapping crystalline building blocks within coccoliths.
• Demonstrated the ability to decipher the complex network of biomineral superstructures at high resolution.

Conclusions:

• 4D-STEM offers significant opportunities for understanding the crystallography of intricate biominerals.
• Parallel data acquisition and automated analysis enhance the throughput for deciphering complex biomineral architectures.