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23 mai 2019: 1 événement

séminaire

  • Séminaires Internes

    Jeudi 23 mai 11:00-12:00 - Dag Kristian Dysthe

    [INTERNE] Molecular layer resolution of crystal growth in nanoconfinement

    Résumé : Confined crystal growth is a common situation in Nature. Shells, coccoliths and human teeth and bones are minerals that are shaped partially by confinement. Crystallization in confinement can exert a pressure and cause rocks, concrete and bricks to break, destroying buildings and historical monuments all over the world.
    Almost all studies on crystal growth are, however performed in an environment where the effects of an additional interface can be neglected. In order to image the nanoconfined crystallization process in situ we developed an experiment based on reflection interference contrast microscopy. This allows in situ observations with spatial and temporal resolution that allows us to track the step flow of individual molecular layers of Ångstrøm thickness. Our experiments reveal details of different growth processes in nanoconfinement of our model system NaClO3, such as deformed spiral growth from dislocations, 2D nucleation fluctuations, the birth of cavities, orientation dependent step flow in a concentration gradient and the appearance of a novel Mullins-Sekerka-like instability.

    En savoir plus : Séminaires Internes