Darkins R, McPherson IJ, Ford IJ, Duffy DM, Unwin PR. Critical Step Length as an Indicator of Surface Supersaturation during Crystal Growth from Solution.
CRYSTAL GROWTH & DESIGN 2022;
22:982-986. [PMID:
35572167 PMCID:
PMC9097158 DOI:
10.1021/acs.cgd.1c01249]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 01/11/2022] [Indexed: 06/15/2023]
Abstract
The surface processes that control crystal growth from solution can be probed in real-time by in situ microscopy. However, when mass transport (partly) limits growth, the interfacial solution conditions are difficult to determine, precluding quantitative measurement. Here, we demonstrate the use of a thermodynamic feature of crystal surfaces-the critical step length-to convey the local supersaturation, allowing the surface-controlled kinetics to be obtained. Applying this method to atomic force microscopy measurements of calcite, which are shown to fall within the regime of mixed surface/transport control, unites calcite step velocities with the Kossel-Stranski model, resolves disparities between growth rates measured under different mass transport conditions, and reveals why the Gibbs-Thomson effect in calcite departs from classical theory. Our approach expands the scope of in situ microscopy by decoupling quantitative measurement from the influence of mass transport.
Collapse