Editing Refrigeration (section)

===Magnetic refrigeration===
{{Main|Magnetic refrigeration}}
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Magnetic refrigeration, or [[adiabatic]] [[demagnetization]], is a cooling technology based on the magnetocaloric effect, an [[intrinsic and extrinsic properties|intrinsic property]] of magnetic solids. The refrigerant is often a [[paramagnetism|paramagnetic]] [[salt (chemistry)|salt]], such as [[cerium]] [[magnesium]] [[nitrate]]. The active [[magnetic field|magnetic]] [[dipole]]s in this case are those of the [[electron shell]]s of the paramagnetic atoms.

A strong magnetic field is applied to the refrigerant, forcing its various magnetic dipoles to align and putting these degrees of freedom of the refrigerant into a state of lowered [[entropy]]. A heat sink then absorbs the heat released by the refrigerant due to its loss of entropy. Thermal contact with the heat sink is then broken so that the system is insulated, and the magnetic field is switched off. This increases the heat capacity of the refrigerant, thus decreasing its temperature below the temperature of the heat sink.

Because few materials exhibit the needed properties at room temperature, applications have so far been limited to [[cryogenics]] and research.