In situ X-ray studies of adlayer-induced crystal nucleation at the liquid-liquid interface.
Proc Natl Acad Sci U S A
; 110(17): 6663-8, 2013 Apr 23.
Article
en En
| MEDLINE
| ID: mdl-23553838
ABSTRACT
Crystal nucleation and growth at a liquid-liquid interface is studied on the atomic scale by in situ Å-resolution X-ray scattering methods for the case of liquid Hg and an electrochemical dilute electrolyte containing Pb(2+), F(-), and Br(-) ions. In the regime negative of the Pb amalgamation potential Φ(rp) = -0.70 V, no change is observed from the surface-layered structure of pure Hg. Upon potential-induced release of Pb(2+) from the Hg bulk at Φ > Φ(rp), the formation of an intriguing interface structure is observed, comprising a well-defined 7.6-Å-thick adlayer, decorated with structurally related 3D crystallites. Both are identified by their diffraction peaks as PbFBr, preferentially aligned with their axis along the interface normal. X-ray reflectivity shows the adlayer to consist of a stack of five ionic layers, forming a single-unit-cell-thick crystalline PbFBr precursor film, which acts as a template for the subsequent quasiepitaxial 3D crystal growth. This growth behavior is assigned to the combined action of electrostatic and short-range chemical interactions.
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1
Banco de datos:
MEDLINE
Asunto principal:
Cristalización
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Electroquímica
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Electrólitos
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Mercurio
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Modelos Químicos
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Año:
2013
Tipo del documento:
Article
País de afiliación:
Alemania