Editing Magnetocaloric effect (section)

{{short description|Phenomenon where a material changes temperature due to a magnetic field}}
[[File:Magnetocaloric1.01cr.png|thumb|[[Gadolinium]] alloy heats up inside the magnetic field and loses thermal energy to the environment, so it exits the field and becomes cooler than when it entered.]]

The '''magnetocaloric effect''' ('''MCE''', from ''[[magnet]]'' and ''[[calorie]]'') is a scientific phenomenon in which certain materials warm up when a magnetic field is applied. The warming is due to changes in the internal state of the material releasing heat. When the magnetic field is removed, the material returns to its original state, reabsorbing the heat, and returning to original temperature. This can be used to achieve refrigeration, by allowing the material to radiate away its heat while in the magnetized hot state. Removing the magnetism, the material then cools to below its original temperature.

The effect was first observed in 1881 by a German physicist [[Emil Warburg]], followed by French physicist [[Pierre Weiss|P. Weiss]] and Swiss physicist [[Auguste Piccard|A. Piccard]] in 1917.<ref name="Weiss 103–109">{{cite journal |last1=Weiss |first1=Pierre |last2=Piccard |first2=Auguste |title=Le phénomène magnétocalorique |journal=J. Phys. (Paris) |volume=5th Ser. |issue=7 |pages=103–109 |date=1917}}<br/>{{cite journal |last=Smith |first=Anders |title=Who discovered the magnetocaloric effect? |journal=The European Physical Journal H |volume=38 |issue=4 |pages=507–517 |date=2013 |doi=10.1140/epjh/e2013-40001-9|bibcode = 2013EPJH...38..507S |s2cid=18956148 }}</ref> The fundamental principle was suggested by [[Peter Debye|P. Debye]] (1926) and [[William Giauque|W. Giauque]] (1927).<ref>{{cite book | last = Zemansky | first = Mark W. | title = Temperatures very low and very high | publisher = Dover | date = 1981 | location = New York | page = 50 | isbn = 0-486-24072-X }}</ref> The first working magnetic refrigerators were constructed by several groups beginning in 1933.  Magnetic refrigeration was the first method developed for cooling below about 0.3 K (the lowest temperature attainable before magnetic refrigeration, by pumping on [[Helium-3|{{chem|3|He}}]] vapors).

The magnetocaloric effect can be used to attain extremely low [[temperature]]s, as well as the ranges used in common [[refrigerator]]s.<ref>{{cite journal | last1 = França | first1 = E.L.T. | last2 = dos Santos | first2 = A.O. | last3 = Coelho | first3 = A.A. | year = 2016 | title = Magnetocaloric effect of the ternary Dy, Ho and Er platinum gallides | journal = Journal of Magnetism and Magnetic Materials | volume = 401 | pages = 1088–1092 | doi = 10.1016/j.jmmm.2015.10.138 | bibcode = 2016JMMM..401.1088F }}</ref><ref name="doi10.1088/0022-327/38/23/R01">{{Cite journal | doi = 10.1088/0022-3727/38/23/R01| title = Developments in magnetocaloric refrigeration| journal = Journal of Physics D: Applied Physics| volume = 38| issue = 23| pages = R381–R391| year = 2005| last1 = Brück | first1 = E. |bibcode = 2005JPhD...38R.381B | s2cid = 122788079}}</ref><ref name="auto">{{Cite journal | doi = 10.1002/pssb.201451217| title = Magnetocaloric effect in "reduced" dimensions: Thin films, ribbons, and microwires of Heusler alloys and related compounds| journal = Physica Status Solidi B| volume = 251| issue = 10| pages = 2104| year = 2014| last1 = Khovaylo | first1 = V. V. | last2 = Rodionova | first2 = V. V. | last3 = Shevyrtalov | first3 = S. N. | last4 = Novosad | first4 = V. |bibcode = 2014PSSBR.251.2104K | s2cid = 196706851}}</ref><ref name="auto1">{{Cite journal | doi = 10.1016/j.ijrefrig.2008.01.004| title = Thirty years of near room temperature magnetic cooling: Where we are today and future prospects| journal = International Journal of Refrigeration| volume = 31| issue = 6| pages = 945| year = 2008| last1 = Gschneidner | first1 = K. A. | last2 = Pecharsky | first2 = V. K. | url = https://zenodo.org/record/1259069}}</ref>