What is the Curie Temperature?
Named after Pierre Curie, the Curie temperature indicates the temperature above which ferroelectric or ferromagnetic properties of a material are lost. Above this temperature, the characteristics of the material are then only paraelectric or paramagnetic.
This process of paraelectrification or paramagnetization is reversible. This means that magnetic properties of materials return as soon as the temperature decreases again.
The Curie temperature varies from high to low depending on the magnetic material and can be as high as 1150°C for cobalt, for example.
Good to know: already below the Curie temperature of a material, the polarization of a permanent magnet is permanently lost.
In principle, ferrite magnets are more temperature-resistant than neodymium magnets. Depending on the composition, the Curie temperature for ferrites is between 100°C and 460°C.
What are the application areas of the Curie temperature?
One area of application of the Curie temperature is, for example, the process of data storage. In this process, storage media that have previously been written to magnetically are heated to the Curie temperature with the aid of a laser. This deletes existing data records so that new ones can be written to them. This process is particularly used for top-secret information because the data is deleted without leaving any residue.