An electric motor includes a stator and a rotor. One of the stator and the rotor includes a magnetic core, preferably an iron core. A reactive metal or a mixture or reactive metals is fixed to the magnetic core. The or each reactive metal has a reactivity greater than the reactivity of the metal of the magnetic core. A rotor and a stator is also provided. By fixing the reactive metal or metal mixture to the magnetic core of the motor, rotor or stator, oxidation and corrosion of the core can be avoided or reduced.