Laminated CoZr amorphous thin-film recording heads

Recording heads with four-layer laminated CoZr/Ta films as pole pieces have been fabricated using rf sputter deposition and ion milling techniques. Typical 4πMs of 14 000 G were obtained for CoZr amorphous films compared with 10 000 G for Permalloy films. Recording tests performed with this laminated CoZr/Ta film head indicate 8-12 dB better overwrite than with plated Permalloy film heads having an identical structure. However, the former exhibits a 10%-25% lower amplitude than the latter. This may be attributed to the thermal degradation of the initial permeability μi of the CoZr film during head-fabrication processes. This CoZr/Ta head also shows poorer amplitude stability than the plated Permalloy head.