Mechanistic Insights into Defect-Mediated Crystallization Revealed by Lattice Strain Evolution

Area of Science:

• Materials Science
• Crystallography
• Geochemistry

Background:

• Structural defects and lattice strain are inherent to crystalline materials.
• Their precise roles in chemical reactions and crystal growth pathways are not fully understood.

Purpose of the Study:

• To investigate the 3D evolution of nanoscale strain and defects during barite (BaSO4) and calcite (CaCO3) crystal growth.
• To elucidate the impact of these defects on crystal structure, ion incorporation, and chemical reactivity.

Main Methods:

• Coherent X-ray scattering
• Electron microscopy
• Molecular simulations

Main Results:

• Calcite crystals exhibited increasing strain and developed dislocation defects during growth, unlike barite.
• Strontium incorporation (Sr2+) in Sr-rich solutions modulated calcite's lattice structure, increasing strain.
• Calcite crystallization involved precursor phases, leading to defect-rich domains.

Conclusions:

• Lattice strain and defects significantly influence calcite crystallization dynamics and reactivity.
• Defect formation and ion incorporation are key factors in controlling crystal growth.
• This research provides fundamental insights into strain heterogeneity's role in ionic crystal chemistry.