Mu-metal, in English permalloy, is a magnetic material made of nickel and iron. Mu metal belongs to the ferromagnetic materials with a high relative permeability
, which can be up to 100,000 and above. The hysteresis of Mu-metal is very steep and the magnetic field strength
Mu-metal is used to shield magnetic fields and conducts low frequency magnetic fields. It is used in magnetoresistive components such as GMR sensors and AMR sensors as well as for shielding magnetic fields from transformers, power supplies or entire rooms.