Stability of
the polar {111} NaCl crystal face
Neda Radenovi, Daniel Kaminski, Willem van Enckevort, Sander
Graswinckel, Ismail Shah, Mendel in 't Veld, Rienk Algra, and Elias
Vlieg
J. Chem. Phys. 124 (2006) 164706 1-6
Abstract:
We present a surface x-ray diffraction determination of the {111}
NaCl-liquid interface structure. Using ultrathin water or formamide
liquid layers we ascertained that the crystal surface is smooth at an
atomic level and is not reconstructed. Our results reveal surprisingly
small differences in surface structure between the two cases, which
nevertheless lead to dramatic differences in crystal morphology. We
determined that the rocksalt {111} surface is Na+ terminated for both
environmental conditions. A quarter to half a monolayer of laterally
disordered Cl– ions is located on top of a fully ordered Na+ crystal
surface with occupancy 0.75–1.0. This means that the polar surface is
stabilized through the formation of an electrochemical double layer.