Neodymium magnets perform better at lower temperatures, they even get stronger as the temperature gets lower. The lowest working temperature of neodymium magnets is around -138 ºC (135 K, -216 ºF), they performance best at this temperature. When the temperature drops below -138 ºC, the performance of neodymium magnets drops rapidly. However, the rapid decrease in magnetism below -138 ºC is reversible. When the temperature rises above -138 ºC, the neodymium magnets still show good performance.
The maximum working temperature of neodymium magnets is generally determined by the material. The suffixes of neodymium magnet grades represent the maximum working temperature like this:
Suffix Working Temperature
No suffix 80℃
If the temperature of the neodymium magnet exceeds its working temperature, the magnet will start to demagnetize. Many reports describe this demagnetization as irreversible, because even if the temperature decrease below the working temperature later on, the magnetism of neodymium magnet cannot be restored. In fact, the structure of the neodymium magnet itself has not been destroyed, and it can still be used after the magnet is magnetized.