Perpendicular Anisotropy of Electrodeposited Nickel and Nickel-Phosphorus Films

The perpendicular anisotropy, which has its easy axis perpendicular to the film surface, was measured for electrodeposited Ni and Ni-P films containing up to 7 at % P, and also for an annealed film at temperature up to 400°C. These measurements were correlated with the magnetization, the internal stress and the structure of the films. The perpendicular anisotropy for a Ni film is explained only in a term of the magneto-stress term of -3/2λσ. On the other hand, for Ni-P films it is caused by the anomalous term, whose origin is due to the existence of non-magnetic high phosphorus-nickel region elongated perpendicular to the film surface. Such an existence of the inhomogeneous distribution of phosphorus is suggested experimentally. The anomalous term is quantitatively explained by this model.