Magnetostriction of Fe-Co Alloy Films and Its Control by Multilayering

The bec Fe
70
Co
30
alloy has a high saturation magnetization and a large positive magnetostriction, whereas the fcc Ni
75
Co
25
alloy has a large negative magnetostriction value. This paper reports the results of a systematic investigation into the magnetic properties of FeCo/NiCo multilayer films. Magnetostriction in an FeCo/NiCo film becomes smaller as the ratio of the thickness of the NiCo layer to that of the FeCo/NiCo film increases. The film (3/7 nm) has a saturation magnetization of 120 emu/g and a coercivity of 1.7 Oe, with nearly zero magnetostriction.