|
Curie point (or the Curie temperature, temperature of the second-order phase transition)
Curie point (or the Curie temperature, temperature of the second-order phase transition)
D.E.V.I.C.E. is an encyclopedia of terms used by manufacturers of test and measurement equipment. T&M Atlantic created this service to better explain the functionality of instruments it offers, and to highlight the latest developments in the world of measurement equipment. We are using such tools as animation to bring words and pictures to life and to create not just an understanding but also an appreciation for technology that goes into the design of every instrument.
D.E.V.I.C.E. on Request
If you are searching for a particular term or definition, please contact us and our engineers will be glad to explain it to you.
In general Curie point (or the Curie temperature, temperature of the second-order phase transition) is associated with an abrupt change in the symmetry properties of a substance (for example, magnetic – in ferromagnets, electric – in ferroelectrics, crystal chemical – in ordered alloys). Named after Pierre Curie who studied this transition in a detail in ferromagnets.
At a temperature (T) below the Curie point (Q) ferromagnets have spontaneous magnetization and some certain magneto-crystalline symmetry. At the Curie point (T = Q) the intensity of the thermal motion of ferromagnet atoms is sufficient to destroy its spontaneous magnetization (“magnetic order”) and change the symmetry, as a result, the ferromagnet becomes a paramagnet.
In ferroelectrics and antiferroelectrics at T = Q the thermal motion of atoms reduces to zero the spontaneous ordered orientation of the electric dipoles of the elementary cells of the crystal lattice.
In ordered alloys at the Curie point the degree of long-range order in the atoms (ions) arrangement of the alloy components becomes equal to zero.
Thus in all cases of second-order phase transitions at T = Q some type of atomic order disappears in a substance. Closer to the Curie point there are specific changes in many physical properties (for example, heat capacity, magnetic susceptibility, etc.) occur in a substance, reaching its maximum at T = Q which is usually used to accurately determine the phase transition temperature.
Back to the list
Rating Search by section
D.E.V.I.C.E. services
|
|