Preparation of functionally graded magnetic films by an electrochemical method

Gradient control of magnetic properties, such as coercivity, Hc, in electrochemically-deposited thin films was attempted in order to establish the methodology for the preparation of functionally graded magnetic thin films. By applying ultra-thin "seed" layers of CoB or CoP, the Hc of electroless CoNiP films growing on them can be controlled toward the film thickness direction. Furthermore, sequential control of the rotating speed of substrates during the deposition can achieve programmed control of the gradient in Hc. These procedures are expected to be useful methods for optimizing graded magnetic properties of the films as recording media which are suitable for the overall system parameters such as local gradient of the recording head field.