Electrocaloric effect

From Online Dictionary of Crystallography

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== Definition ==
== Definition ==
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The electrocaloric effect is the converse of the pyroelectric effect: it describes the electrical response of a material to a thermal impetus. For instance, if the material is submitted uniformly to a temperature variation &delta;&Theta;, an electrical polarisation ''P<sub>i</sub> '' appears:
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The electrocaloric effect is the converse of the pyroelectric effect: it describes the variation of entropy &delta;&sigma; of a material submitted to an electrical field ''E<sub>i</sub> '':
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''P<sub>i</sub> '' = ''p<sub>i</sub><sup>T</sup> ''&delta;&Theta;
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''&delta;&sigma;'' = ''p<sub>i</sub><sup>T</sup>'' ''E<sub>i</sub> ''
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where ''p<sub>i</sub><sup>T</sup>'' is the electrocaloric coefficient at constant stress. It is equal to the pyroelectric coefficient.
where ''p<sub>i</sub><sup>T</sup>'' is the electrocaloric coefficient at constant stress. It is equal to the pyroelectric coefficient.
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== See also ==
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[http://www.iucr.org/iucr-top/comm/cteach/pamphlets/18/ An introduction to crystal physics]  (Teaching Pamphlet of the ''International Union of Crystallography'')<br>
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Section 10.2 of ''International Tables of Crystallography, Volume A''<br>
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Section 1.1.4 and part 3 of ''International Tables of Crystallography, Volume D''
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----
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[[Category:Physical properties of crystals]]<br>

Revision as of 09:30, 12 January 2007

Effet électrocalorifique (Fr).

Definition

The electrocaloric effect is the converse of the pyroelectric effect: it describes the variation of entropy δσ of a material submitted to an electrical field Ei :

δσ = piT Ei

where piT is the electrocaloric coefficient at constant stress. It is equal to the pyroelectric coefficient.

See also

An introduction to crystal physics (Teaching Pamphlet of the International Union of Crystallography)
Section 10.2 of International Tables of Crystallography, Volume A
Section 1.1.4 and part 3 of International Tables of Crystallography, Volume D