The fabrication of multi-nano-layer structures can in some cases be achieved electrochemically if for example the plating current density has a significant effect on the deposit composition or if reverse-plating changes the composition. Moreover the realisation of a multi-nano-layer structure can also crucially affect the properties of the material. This chapter will look at one material system in which both of the above apply namely amorphous Co-P.
When produced using conventional DC plating, amorphous Co-P tends to ex-hibit perpendicular magnetic anisotropy and hence very low permeability and somewhat high coercivity. This limits the usefulness of the material as a magnetic core for power conversion applications which require low coercivity, high satura-tion magnetisation, high permeability, high anisotropy field and high resistivity. Riveiro et al. used pulse reverse plating to fabricate multi-layers of alternate mag-netic and non-magnetic materials. With the thickness of the magnetic layers at around 30 nm, they were able to achieve in plane anisotropy and low coercivity 8 A m-1.
This chapter will describe the early work and a selection of subsequent research on multi-nano-layers of amorphous Co-P, e.g. Perez et al. who used pulse plating and McCloskey et al. who improved the saturation magnetisation and thermal stability of the material.