Phase transitions

sometimes called dimerization

cellular automaton

thumb|upright=1.3|Scanning Electron Microscope interface image of a fayalite-[[pyroxene symplectite (at right) in a Martian meteorite]] A symplectite (or symplektite) is a material texture: a micrometre-scale or submicrometre-scale intergrowth of two or more crystals. Symplectites form from the breakdown of unstable phases, and may be composed of minerals, ceramics, or metals. Fundamentally, their formation is the result of slow grain-boundary diffusion relative to interface propagation rate.

300px|thumb|Pressure–temperature phase diagram, including an illustration of the liquid–liquid transition line proposed for several polyamorphous materials. This liquid–liquid [[phase transition would be a first order, discontinuous transition between low and high density liquids (labelled 1 and 2). This is analogous to polymorphism of crystalline materials, where different stable crystalline states (solid 1, 2 in diagram) of the same substance can exist (e.g. diamond and graphite are two polymorphs of carbon). Like the ordinary liquid–gas transition, the liquid–liquid transition is expected t

when the composition of the liquid formed during melting is the same as that of the solid

magnetic phase transition in α-Fe2O3 hematite

Melting points of chemical mixtures

thumb|right|200px|Simple sublimation apparatus. Water usually cold, is circulated in cold finger to allow the desired compound to be deposited.1 Cooling water in 2 Cooling water out 3 Vacuum/gas line 4 Sublimation chamber 5 Sublimed compound 6 Crude material 7 External heating A sublimatory or sublimation apparatus is equipment, commonly laboratory glassware, for purification of compounds by selective sublimation. In principle, the operation resembles purification by distillation, except that the products do not pass through a liquid phase.

minimum particle size from which an aggregate is thermodynamically stable

transitions from a metal (material with good electrical conductivity of electric charges) to an insulator (material where conductivity of charges is quickly suppressed)