Importance of knowing the Curie temperature?

[Jon.G]

For a module I recently ran a computer simulation to determine the temperature at which a material underwent a ferromagnetic to paramagnetic phase transition.

However, I'm not really sure what the applications are of knowing this are. Obviously if you wanted the material to retain its permanent magnetism you would need to keep it below this temperature, and if you wanted if to be induced magnetism you would keep it above.
Are there many systems that would need this to avoid, for example, breaking down or data loss/corruption?

 

[Aceix]

This is important so you know the kind of material needed for the right job. It has also been used to confirm the fact that it is not due to the presence of iron in the core of Earth that had caused the magnetic field.

Aceix.