Our Calculations - Aluminium/Alumina

    1. Aluminium/Alumina with Adham Hashibon and Geri Wagner from our group and Wayne Kaplan and students/postdocs on the experimental side.

    2. A drop of aluminium on an alumina (sapphire - aluminium oxide) must wet the surface in order to adhere. Metal/ceramic interfaces such as these have important industrial applications, and can be viewed in electron microscopes. (See picture by G. Levi and W. Kaplan.) Our interest is in studying the details of the structure near the interface. We started with a model of aluminium atoms, some fixed in the locations of alumina atoms and some free to move in the aluminium drop. We used Ercolessi-Adams potentials for aluminium initially and are now (G. Wagner) investigating potentials that are suitable for both aluminium and alumina.

    3. We investigated density profiles near the surface as functions of crystallographic orientation and found direct correlations between amount of ordering and substrate orientation.

    4. Visualization was essential both for debugging the complex geometries and for identifying regions of order and disorder.

    5. Examples (data of A. Hashibon, Ercolessi-Adams potentials) :
      1. View mpg or animated gif - a drop of aluminium on an ``alumina'' surface, periodic BCs in y,z free in x
      2. View mpg or animated gif - 2009 atoms at 1000K with 3 ``alumina'' solid layers, center of drop only
      3. View mpg or View - 2009 atoms at 850K with 3 ``alumina'' solid layers, center of drop only

    OOPS! you just saw the first AViz visualizations !