Order-disorder transitions such as in alpha- titanium aluminides.Changes in the crystallographic structure such as between ferrite and austenite of iron.The martensitic transformation which occurs as one of the many phase transformations in carbon steel and stands as a model for displacive phase transformations.The transition between differently ordered, commensurate or incommensurate, magnetic structures, such as in cerium antimonide.The transition between the ferromagnetic and paramagnetic phases of magnetic materials at the Curie point.

Transition to a mesophase between solid and liquid, such as one of the ' liquid crystal' phases.A spinodal decomposition, in which a single phase is cooled and separates into two different compositions of that same phase.A peritectic transformation, in which a two-component single-phase solid is heated and transforms into a solid phase and a liquid phase.A metastable polymorph which forms rapidly due to lower surface energy will transform to an equilibrium phase given sufficient thermal input to overcome an energetic barrier. A metastable to equilibrium phase transformation.The same process, but beginning with a solid instead of a liquid is called a eutectoid transformation. A eutectic transformation, in which a two-component single-phase liquid is cooled and transforms into two solid phases.Phase transitions commonly occur in nature and are used today in many technologies. The measurement of the external conditions at which the transformation occurs is termed the phase transition. For example, a liquid may become gas upon heating to the boiling point, resulting in an abrupt change in volume. During a phase transition of a given medium, certain properties of the medium change, often discontinuously, as a result of the change of external conditions, such as temperature, pressure, or others. Commonly the term is used to refer to changes among the basic states of matter: solid, liquid, and gas, as well as plasma in rare cases.įor example, a phase of a thermodynamic system and the states of matter have uniform physical properties. In chemistry, thermodynamics, and many other related fields, phase transitions (or phase changes) are the physical processes of transition between a state of a medium, identified by some parameters, and another one, with different values of the parameters. This diagram shows the nomenclature for the different phase transitions.

Sheepshaver slowing down