Gibbs-Thomson effect

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The Gibbs-Thomson effect (not to be confused with the Thomson effect) relates surface curvature to vapor pressure and chemical potential. It is named after Josiah Willard Gibbs and three Thomsons: James Thomson, William Thomson, 1st Baron Kelvin, and Sir Joseph John Thomson.

It leads to the fact that small liquid droplets (i.e. particles with a high surface curvature) exhibit a higher effective vapor pressure, since the surface is larger in comparison to the volume.

Another notable example of the Gibbs-Thomson effect is Ostwald ripening, in which concentration gradients cause small precipitates to dissolve and larger ones to grow.

The Gibbs-Thomson equation for a precipitate with radius [R] is:

[\frac} = \exp}\right)}]

[R_ = \frac}]

[ V_ ] : Atomic volume

[ k_B ] : Boltzmann constant

[ p_ ] : Equilibrium partial pressure (or chemical potential or concentration)

[ p ] : Partial pressure (or chemical potential or concentration)

[ T ] : Absolute temperature

Ostwald ripening is thought to occur in the formation of orthoclase megacrysts in granites as a consequence of subsolidus growth. See rock microstructure for more.

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