title: Nanoscale analysis of the morphology and surface stability of calcium carbonate polymorphs.
abstract: Under earth surface conditions, in ocean and natural water, calcium carbonate is ubiquitous, forming anhydrous and hydrous minerals. These hydrous phases are of considerable interest for their role as precursors to stable carbonate minerals. Atomistic simulation techniques have been employed here to perform a comprehensive and quantitative study of the structural and energetic stability of dry and hydrous surfaces of calcium carbonate polymorphs using two recently developed forcefields. Results show that the dry forms are prone to ductility; while hydrous phases are found to be brittle. The (001) surface of monohydrocalcite appears to be the most stable (0.99 J/m(2)) whereas for the ikaite phase, the (001) surface is the most stable. The corresponding value is 0.2 J/m(2), i.e. even lower than the surface energy of the Beautiful computed morphology pictures are obtained with Xiao's model and are very similar to the observed SEM images.
authors.affiliation: Civil Engineering and geo-Environment Laboratory LGCgE- EA 4515 Lille Nord de France, Polytech'Lille. Université Lille 1 Sciences et Technologie, Cité Scientifique, Avenue Paul Langevin, 59655 Villeneuve D'Ascq Cedex, France.
authors.forename: W
authors.initials: W
authors.lastname: Sekkal
authors.forename: A
authors.initials: A
authors.lastname: Zaoui
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry*; D008422:Materials Testing; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D002119:Calcium Carbonate
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