Hydrothermal Atomic Force Microscopy Investigation of Barite Growth: Role of Spectator Ions in Elementary Step Edge Growth Kinetics and Hillock Morphology

作者：Jindra Sarah A; Bertagni Angela L; Bracco Jacquelyn N; Higgins Steven R^*

来源：Crystal Growth & Design, 2017, 17(11): 6085-6095.

DOI：10.1021/acs.cgd.7b01198

To better understand the role of spectator ions in barite growth, the kinetics of step edge growth on barite (001) surfaces were studied under various salt solutions. Hydrothermal atomic force microscopy (HAFM) was used to investigate the effect of background electrolytes (NaCl, NaBr, and NaNO3) as a function of saturation index and ionic strength (I) on barite growth sourced at dislocations at 108 degrees C. Results demonstrate that hillock morphology is affected by I, as well as type of anion, where the prevalence of steps aligned on the [010] direction is highest under Cl-. There is a modest increase in kinetic coefficient of 55-130% with a 10-fold increase in I for each salt. In comparing the kinetic coefficients of the salts at low ionic strength (0.01 M), there is a moderate difference, suggesting that the anion may play a role in barium attachment.

• 出版日期2017-11