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Surface Energy

  1. Dec 13, 2008 #1
    I checked Wiki and ran a forum search, yet I am in need of an explanation of "Surface Energy" that works for me.

    I'm clueless on the concept...

    (btw, just joined physics forums today, seems like a really cool community here...)
  2. jcsd
  3. Dec 14, 2008 #2
    Surface energy is the additional energy per unit surface area for a system of atoms with a surface.

    Imagine that you have a perfect FCC crystal of 3 × 3 × 3 unit cells with periodic boundary conditions in all 3 directions. This means that it is effectively an infinite perfect crystal. Let's call this system A.

    Then you have the same 3 × 3 × 3 unit cells but with periodic boundary conditions in 2 directions. Effectively, this is a thin film with a perfect crystal, and you have two surfaces. Let's call this system B.

    Clearly system B will have higher energy because of the surface.

    Surface Energy = (Energy of B - Energy of A)/(Total Surface Area).

    You can have surface with different crystal orientations, eg (100) or (111) and the surface energy will be different.
  4. Dec 18, 2008 #3
    total surface area of the unit cell ?! or ...
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