Editing Curie temperature (section)

=== Antiferromagnetic and the Néel temperature ===
{{main|Antiferromagnetism}}

Materials are only antiferromagnetic below their corresponding '''Néel temperature''' or '''magnetic ordering temperature''', ''T''<sub>N</sub>. This is similar to the Curie temperature as above the Néel Temperature the material undergoes a [[phase transition]] and becomes paramagnetic. That is, the thermal energy becomes large enough to destroy the microscopic magnetic ordering within the material.<ref name="spaldin">{{cite book|last1=Spaldin|first1=Nicola A.|author-link=Nicola Spaldin |title=Magnetic materials : fundamentals and device applications|date=2006|publisher=Cambridge Univ. Press|location=Cambridge|isbn=9780521016582|pages=89–106|edition=Repr.}}</ref> It is named after [[Louis Néel]] (1904–2000), who received the 1970 [[Nobel Prize in Physics]] for his work in the area.

The material has equal magnetic moments aligned in opposite directions resulting in a zero magnetic moment and a net magnetism of zero at all temperatures below the Néel temperature. Antiferromagnetic materials are weakly magnetic in the absence or presence of an applied magnetic field.

Similar to ferromagnetic materials the magnetic interactions are held together by exchange interactions preventing thermal disorder from overcoming the weak interactions of magnetic moments.<ref name=Hall1/><ref name=Jullien10/> When disorder occurs it is at the Néel temperature.<ref name=Jullien10>{{harvnb|Jullien|Guinier|1989|pp=156–57}}</ref>

Listed below are the Néel temperatures of several materials:<ref>{{cite book |first=Charles |last=Kittel |title=[[Introduction to Solid State Physics]] |edition=8th |location=New York |publisher=John Wiley & Sons |year=2005 |isbn=978-0-471-41526-8 }}</ref>
{| class="wikitable sortable"
|-
! Substance
! Néel temperature ([[kelvin|K]])
|-
| [[Manganese(II) oxide|MnO]]
| 116
|-
| [[Manganese(II) sulfide|MnS]]
| 160
|-
| [[Manganese(II) telluride|MnTe]]
| 307
|-
| [[Manganese(II) fluoride|MnF<sub>2</sub>]]
| 67
|-
| [[Iron(II) fluoride|FeF<sub>2</sub>]]
| 79
|-
| [[Iron(II) chloride|FeCl<sub>2</sub>]]
| 24
|-
| [[Iron(II) iodide|FeI<sub>2</sub>]]
| 9
|-
| [[Iron(II) oxide|FeO]]
| 198
|-
| [[Iron oxychloride|FeOCl]]
| 80
|-
| [[Chromium(II) chloride|CrCl<sub>2</sub>]]
| 25
|-
| [[Chromium(II) iodide|CrI<sub>2</sub>]]
| 12
|-
| [[Cobalt(II) oxide|CoO]]
| 291
|-
| [[Nickel(II) chloride|NiCl<sub>2</sub>]]
| 50
|-
| [[Nickel(II) iodide|NiI<sub>2</sub>]]
| 75
|-
| [[Nickel(II) oxide|NiO]]
| 525
|-
| KFeO<sub>2</sub>
| 983<ref>{{cite journal |last1=Ichida |first1=Toshio |title=Mössbauer Study of the Thermal Decomposition Products of K2FeO4 |journal=Bulletin of the Chemical Society of Japan |date=1973 |volume=46 |issue=1 |pages=79–82 |doi=10.1246/bcsj.46.79|doi-access=free }}</ref>
|-
| [[Chromium|Cr]]
| 308
|-
| [[Chromium(III) oxide|Cr<sub>2</sub>O<sub>3</sub>]]
| 307
|-
| Nd<sub>5</sub>Ge<sub>3</sub>
|50
|}