Britannica Sources used in this answer

How do permanent magnets differ from temporary magnets?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Learn about magnetic fields and the levels of particles, atoms, crystals, and domains — magnet Magnetic fields and the levels of magnetism of particles, atoms, crystals, and domains.

The primary difference between permanent and temporary magnets lies in their ability to retain magnetism after an external magnetizing force is removed.

Permanent Magnets: These materials retain their magnetism once the magnetizing force is withdrawn. Their performance is characterized by high remanent flux density ( $B_{r}$ ) and high coercive force ( $H_{c}$ ), which allow them to resist demagnetization. Materials like steel are effective for this purpose because they contain internal obstacles—such as impurities or precipitates—that "lock" magnetic domain walls in place, preventing them from returning to their original, unmagnetized state.123
Temporary Magnets: In contrast, materials that act as temporary magnets do not maintain significant magnetism once the external field is removed. In pure, homogeneous materials with few internal imperfections, domain walls move easily when a field is applied but return to their original positions when the field is withdrawn, resulting in little to no residual magnetization.3

Essentially, a permanent magnet requires a large reversed magnetic field to be demagnetized, whereas a temporary magnet loses its alignment as soon as the influencing field is gone.3