The temperature at which a magnetic material loses its permanent magnetization is called the Curie temperature or Curie point.

Here's a bit more about it:

* Ferromagnetism: Materials like iron, nickel, and cobalt exhibit ferromagnetism below their Curie temperature. This means they can be permanently magnetized.

* Paramagnetism: Above the Curie temperature, these materials become paramagnetic, meaning they lose their permanent magnetization and are only weakly attracted to a magnetic field.

* Thermal Agitation: As the temperature of a ferromagnetic material increases, the thermal energy of the atoms increases. This energy disrupts the alignment of magnetic domains, leading to a decrease in magnetization.

Examples:

* Iron's Curie temperature is around 770°C (1418°F).

* Nickel's Curie temperature is around 358°C (676°F).

Let me know if you have any other questions!