Electrodeposition of magnetic materials for thin-film heads

Electrodeposition processes have been extensively used in thin-film head fabrication. Extremely fine features can be produced using photolithographic pattern definition followed by electroplating. Permalloy has been exclusively used for the pole material. Some critical aspects, such as film composition, magnetostriction, and stress level, were found to have a significant effect on head performance. Attempts were made to produce single-domain pole structures by lamination to eliminate output instability caused by nonrepeatable domain wall motions. Alternative improvements were brought about by increasing H/sub k/ and thus reducing the size of the closure domains. Electroplated CoFe and CoFe ternary alloy thin films were found to have very high saturation magnetization ( approximately 1.9 T). The CoFe ternary alloy has rotatable anisotropy. Higher permeability can be obtained by electroplating under an alternatingly switched field.<
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