Configurational dependence of the read-write properties of thin film heads

An experimental study to obtain the optimal configuration for a given frequency range is reported. Heads with pole lengths between 1.6 and 3.5 μm, gap lengths of 0.5 and 0.3 μm, 23 or 30 windings, and flying height of 0.2 μm have been prepared. The heads have been tested on thin-film disks with coercivities, H_c, of 650, 850, and 1100 Oe. The frequency response function and the form of the single pulses have been calculated. The spectral function of the reproduce voltage of a series of pulses with increasing frequency has been determined. The calculated single pulses and peak shift values show reasonable agreement between experiment and theory. Overwrite values show that disks with H_c up to 1100 Oe can be saturated by fields that can be achieved without significant saturation effects in the poles of the magnetic heads with pole lengths >2 μm and 0.3-μm gap length. The resolution increases with increasing pole length and increasing H_c of the disk. Larger pole lengths result in better peak shift values for densities higher than 12 KFCI