1. The structure of PbCl2 on the {100} surface of NaCl and its consequences for crystal growth.
- Author
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Townsend, Eleanor R., Brugman, Sander J. T., Blijlevens, Melian A. R., Smets, Mireille M. H., de Poel, Wester, van Enckevort, Willem J. P., Meijer, Jan A. M., and Vlieg, Elias
- Subjects
LEAD chlorides ,CRYSTAL growth ,SALT ,ATOMIC structure ,CRYSTAL structure ,FERROCYANIDES ,X-ray diffraction - Abstract
The role that additives play in the growth of sodium chloride is a topic which has been widely researched but not always fully understood at an atomic level. Lead chloride (PbCl
2 ) is one such additive which has been reported to have growth inhibition effects on NaCl {100} and {111}; however, no definitive evidence has been reported which details the mechanism of this interaction. In this investigation, we used the technique of surface x-ray diffraction to determine the interaction between PbCl2 and NaCl {100} and the structure at the surface. We find that Pb2+ replaces a surface Na+ ion, while a Cl− ion is located on top of the Pb2+ . This leads to a charge mismatch in the bulk crystal, which, as energetically unfavourable, leads to a growth blocking effect. While this is a similar mechanism as in the anticaking agent ferrocyanide, the effect of PbCl2 is much weaker, most likely due to the fact that the Pb2+ ion can more easily desorb. Moreover, PbCl2 has an even stronger effect on NaCl {111}. [ABSTRACT FROM AUTHOR]- Published
- 2018
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