Rare Earth Magnet Basics / Glossary of Magnet Terms /Aging demagnetization
- Aging demagnetization
- This is a phenomenon in which the magnetic flux of a permanent magnet decreases with time. Even though we say "permanent magnets", they do not remain magnets permanently. Over a long period time, permanent magnets are gradually demagnetized by the impact of heat fluctuation. The degree of deterioration depends on the type and material of magnet and the magnetic characteristics. Even for the same type of magnet with the same characteristics, the degree of deterioration varies with the magnet shape, magnetic circuit configuration (permeance coefficient) and temperature. Generally, the lower the usage temperature and the higher the permeance coefficient and also the higher the Curie temperature and the higher the coercive force of the material, the less the change over time. You can obtain data on the amount of change over time for Shinetsu rare earth magnets from our download page.
