Morphology and Surface Structure of Silver Carboxylates
E. Aret, V. Volotchaev, S. Verhaegen, H. Meekes, E. Vlieg, G. Deroover and C. van Roost
Cryst. Growth & Design 6 (2006) 1027-1032

Abstract:
The crystal morphology of silver laurate, silver stearate, and silver behenate is studied. The crystal structures form a homologous series for AgOOCnH2n-1 (for n = even). These crystals are morphologically only isomorphous when grown at low supersaturation. The morphological importance of the top facets depends on the supersaturation as well as on the carbon chain length. The surface topology is studied on a molecular scale with the use of atomic force microscopy. For all facets, a two-dimensional birth-and-spread mechanism is found. The measured surface structure combined with molecular visualization tools leads to a detailed understanding of the growth and shape of these silver carboxylates. The silver-oxygen bonds mainly determine the morphology of the short chain compounds, while the stacking of the carbon chains becomes more important for the long chain compounds. The position of the silver ions on the surface is relevant for understanding the reactivity in photothermographic applications.