Editing Coercivity (section)

{{Short description|Resistance of a ferromagnetic material to demagnetization by an external magnetic field}}
{{About|the property of magnetic fields|other uses|Coercion (disambiguation)}}

[[Image:B-H loop.png|thumb|upright=1.5|A family of hysteresis loops for [[grain-oriented electrical steel]], a soft magnetic material. ''B''<sub>R</sub> denotes ''[[retentivity]]'' and ''H''<sub>C</sub> is the ''coercivity''.  The wider the outside loop is, the higher the coercivity. Movement on the loops is counterclockwise.]]

'''Coercivity''', also called the '''magnetic coercivity''', '''coercive field''' or '''coercive force''', is a measure of the ability of a [[ferromagnetic]] material to withstand an external [[magnetic field]] without becoming [[Magnetization|demagnetized]]. Coercivity is usually measured in [[oersted]] or [[ampere]]/meter units and is denoted {{math|''H''<sub>C</sub>}}.

An analogous property in [[electrical engineering]] and [[materials science]], '''electric coercivity''', is the ability of a [[ferroelectric]] material to withstand an external [[electric field]] without becoming [[polarization density|depolarized]].

Ferromagnetic materials with high coercivity are called magnetically ''hard'', and are used to make [[permanent magnet]]s.  Materials with low coercivity are said to be magnetically ''soft''.  The latter are used in  [[transformer]] and [[inductor]] [[magnetic core|cores]], [[recording head]]s, [[microwave]] devices, and [[magnetic shielding]].