Mixtures A binary phase diagram showing the most stable chemical compounds of titanium and nickel at different mixing ratios and temperatures. Another example is the transition between differently ordered, commensurate or incommensurate, magnetic structures, such as in cerium antimonide. The most well-known is the transition between the ferromagnetic and paramagnetic phases of magnetic materials, which occurs at what is called the Curie point. Phase transitions can also describe the change between different kinds of magnetic ordering. See also: Magnetic structure A phase diagram showing different magnetic structures in the same crystal structure of Manganese monosilicide. 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. As with states of matter, there are also a metastable to equilibrium phase transformation for structural phase transitions. Order-disorder transitions such as in alpha- titanium aluminides. The martensitic transformation occurs as one of the many phase transformations in carbon steel and stands as a model for displacive phase transformations. The change from one crystal structure to another, from a crystalline solid to an amorphous solid, or from one amorphous structure to another ( polyamorphs) are all examples of solid to solid phase transitions. In elements, this is known as allotropy, whereas in compounds it is known as polymorphism. Phase transitions can also occur when a solid changes to a different structure without changing its chemical makeup. See also: Polymorphism (materials science) A phase diagram showing the allotropes of iron, distinguishing between different several different crystal structures including ferrite (α-iron) and austenite (γ-iron). Types of phase transition States of matter A simplified phase diagram for water, showing whether solid ice, liquid water, or gaseous water vapor is the most stable at different combinations of temperature and pressure. The identification of the external conditions at which a transformation occurs defines the phase transition point. This can be a discontinuous change for example, a liquid may become gas upon heating to its boiling point, resulting in an abrupt change in volume. During a phase transition of a given medium, certain properties of the medium change as a result of the change of external conditions, such as temperature or pressure. A phase of a thermodynamic system and the states of matter have uniform physical properties. Commonly the term is used to refer to changes among the basic states of matter: solid, liquid, and gas, and in rare cases, plasma. In chemistry, thermodynamics, and other related fields, a phase transition (or phase change) is the physical process of transition between one state of a medium and another. This diagram shows the nomenclature for the different phase transitions. Physical process of transition between basic states of matter
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