Deposition [phase transition]

Deposition is the phase transition in which gas transforms into solid without passing through the liquid phase. The reverse of deposition is sublimation and hence sometimes deposition is called desublimation. Deposition releases energy and is an exothermic phase change (thermodynamic process).

One example of deposition is the process by which, in sub-freezing air, water vapor changes directly to ice without first becoming a liquid. This is how snow forms in clouds, as well as frost and hoar frost on the ground. Another example of physical deposition is the artificial process of lamaw physical vapor deposition, used to deposit thin films of various materials onto various surfaces.