coercive field

physics

Also known as: coercive force

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June 24, 2026

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In physics, a coercive field, also known as coercive force, refers to the opposing magnetic intensity needed to remove residual magnetism from a magnetized material. This concept is closely related to hysteresis, which describes the lag of magnetization in ferromagnetic materials behind changes in the magnetizing field.12

When a magnetic field is applied to a material like iron, its atomic magnets align. If the field is then reduced to zero, some magnetism remains (remanence). The coercive force is the specific reverse magnetic field strength required to bring this residual magnetism back to zero. Materials with a high coercive force are harder to demagnetize and are used for permanent magnets, while those with a low coercive force are easily magnetized and demagnetized, making them suitable for applications like transformer cores.23

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magnetism
Remanence
…field strength known as the coercive force. Further increase in the reverse field H sets up a reverse field B that again quickly reaches a saturation value S′. Finally, as the reverse field is removed and a positive field applied, B traces out the lower broken line back to a…
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…field strength known as the coercive force. Further increase in the reverse field H sets up a reverse field B that again quickly reaches a saturation value S′. Finally, as the reverse field is removed and a positive field applied, B traces out the lower broken line back to a…
Read More

hysteresis
… is zero is called the coercive force. A further increase in H (in the negative direction) causes the flux density to reverse and finally to reach saturation again, when all the atomic magnets are completely aligned in the opposite direction. The cycle may be continued so that the graph of…
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… is zero is called the coercive force. A further increase in H (in the negative direction) causes the flux density to reverse and finally to reach saturation again, when all the atomic magnets are completely aligned in the opposite direction. The cycle may be continued so that the graph of…
Read More

magnet
Magnetization process
…to zero is H_c, the coercive force, measured in amperes per metre. For a permanent magnet to retain its magnetization without loss over a long period of time, H_c should be as large as possible. The combination of large B_r and large H_c will generally be found in a material…
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…to zero is H_c, the coercive force, measured in amperes per metre. For a permanent magnet to retain its magnetization without loss over a long period of time, H_c should be as large as possible. The combination of large B_r and large H_c will generally be found in a material…
Read More