A Statistical Approach To Explain the Solution Stoichiometry Effect on Crystal Growth Rates

作者：Hellevang Helge^*; Haile Beyene G; Miri Rohaldin

来源：Crystal Growth & Design, 2016, 16(3): 1337-1348.

DOI：10.1021/acs.cgd.5b01466

The solution stoichiometry strongly affects growth rates of ionic compounds, but it has been demonstrated that classically derived analytical growth rate models can only reproduce some of the observed variations. These models do not take into account surface diffusion, and a new statistical model was therefore constructed and solved to see if mechanisms, such as surface transport and ion complexation, can explain some of the discrepancies, between the classical models and observed data. We showed that all experimental data can be reproduced, and the statistical model suggest that surface transport and ion complexation are required to obtain the narrow Gaussian/Lame curves as observed, for example, AgCl. This was explained by the easier surface transport of the neutral complex, and growth units (charged ions) may then be supplied to the growth sites when the complexes are close to surface growth sites. Further numerical or laboratory tests are required to verify if this complexation-surface transport model can indeed be the explanation for some of the variation observed in the experimental data.

• 出版日期2016-3