In a study published in Communications Materials, scientists showed that calcite dissolves fastest in strained regions, revealing how defects and strain drive mineral reactivity and enabling more accurate models of mineral behavior.
Caption: Bragg Coherent Diffraction Imaging (BCDI) images the morphology and strain of calcite particles before (left) and after (right) dissolution in the presence of Pb²⁺. The arrows indicate areas of high strain (indicated by color) where the reaction rate was enhanced. (The semitransparent isosurface on the right is the original pristine morphology, for reference)
Scientific Achievement
Calcite (CaCO3) dissolution is fastest in regions of high local tensile strain (near macrosteps) and alters existing lattice strain. This result reveals the close inter-relationships between strain and chemical reactivity in minerals.
Significance and Impact
While strain and defects are known to influence dissolution rates, their inter-relationships remain unclear. The present results allow the development of strain-aware reactivity models for the accurate prediction of mineral reactivity.
Research Details
- Individual calcite particles were imaged using Bragg coherent diffraction imaging (BCDI) before and after dissolution reaction in acidic solutions in the presence of Pb2+.
- Complementary SEM of the same particles and in-situ X-ray reflectivity visualized morphological changes and quantified Pb2+ incorporation into the top ~1 nm of the calcite lattice.
DOI: 10.18126/zv82-ya03