Thermal stability of the in-plane magnetic anisotropy and the coercivity of nanocrystalline CoFeNi films

By choosing the right production parameters, in-plane, uniaxial anisotropy up to about 15 Oe (1250 J/m3) could be induced in electrodeposited layers of Co59Fe26Ni15. This compound consists of a mixture of FCC and BCC phases. The layers were magnetically soft and nanocrystalline with grain sizes of 10-15 nm. Magnetic and non-magnetic annealing was performed up to 450 deg. C. By magnetic annealing the anisotropy could be increased while the coercivity decreased. A remarkable field-dependent structural effect was found: during magnetic annealing the X-ray diffraction yield from the FCC grains was diminishing, while this yield was growing during non-magnetic annealing. From this we conclude that the domains were small