Magnetic Read-out Head Using Induced RF Permeability Variation in Ni-Fe Thin Film

A field-sensitive type single pole read-out head was trial-fabricated and its characteristics were studied. Play-back sensitivity in the lower recording frequency region declined as the thickness of the Ni-Fe film decreased, but in the higher recording frequency region the read-out output level was independent of Ni-Fe film thickness maintaining an almost constant level, much higher than conventional heads. The carrier-to-noise ratio is also good. These two results show that this type of head is well suited to highly sensitive magnetic read-out heads for high-density magnetic recording.