KEEPERED MEDIA CONTACT HEAD PERFORMANCE OR LIFE BEYOND CONTACT RECORDING/

Longitudinal thin-film rigid disk media with an overlying high permeab ility, low coercivity ''keeper'' layer is shown to improve inductive h ead performance beyond the limit of contact recording. Data taken with a Read-Rite tripad pseudo-contact inductive thin-film head shows that the keeper layer improves peak-detector channel margin by 25% and red uces soft error rate by 6 orders of magnitude. The keeper layer improv es system signal to noise ratio by 3dB to 6dB, and reduces PW-50 from 0.292 mu m (11.5 mu in) to 0.228 mu m (9.0 mu in). A fly height study shows that the keeper layer allows an additional 25nm (1 mu in) higher flying height than standard media for equivalent channel margin or so ft error rates. A model, treating the keeper layer as a magnetic param etric amplifier is proposed. Calculations show that the keeper layer m odulates the inductance of the tripad head by 25 nano-Henrys, or about 5% of the total inductance.