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:

$\backslash frac\{p\}\{p\_\{eq\}\}\; =\; \backslash exp\{\backslash left(\backslash frac\{R\_\{critical\}\}\{R\}\backslash right)\}$

$R\_\{critical\}\; =\; \backslash frac\{2\; \backslash cdot\; \backslash sigma\; \backslash cdot\; V\_\{Atom\}\}\{k\_B\; \backslash cdot\; T\}$

$V\_\{Atom\}$ : Atomic volume

$k\_B$ : Boltzmann constant

$p\_\{eq\}$ : 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.

Thermodynamics | Petrology | Gibbs-Thomson-Effekt