Work function: Difference between revisions

Revision as of 00:08, 10 December 2005

Revision as of 02:08, 30 December 2005

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The '''work function''' is the minimum [[energy]] (usually measured in [[electron volt]]s) needed to remove an [[electron]] from the [[Fermi level]] in a [[metal]] to a point at infinite distance away outside the surface. The work function is generally about half the [[ionization energy]] of a free atom of the metal.


== Example ==

For example, [[Caesium]] has ionization energy 3.9 eV and work function 1.9 eV.

<math> W = -E_{tot}(N+1) + \{E_{tot}(N) + V(\infty) \} = - {\partial E_{tot} \over {\partial N} } + V(\infty) = - \mu + V(\infty) </math>