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When the deep gap field exceeds the onset of the saturation field the fringe-field becomes nonvanishing and retains a plateau value at large distances from the gap corner. The plateau values increase with increasing deep gap field and decrease with the head dimensions; correspondingly, the charge density on the pole surface also increases. The permeability and volume charge distribution near the pole tip corner at large deep gap fields is a sensitive function of the depth below the pole surface and of the extent of the gap saturation. As a result, the divergence of the magnetization in the region immediately below and a fraction of the gap length further below change signs drastically so that the bordering regions are oppositely charged. >

Switching behavior and noise patterns due to an oblique misorientation of the easy axis of a system of noninteracting single domain particles (SDPs) has been investigated. Curvilinear nature of the head field as observed by the particle in the media has been taken into account using Monte Carlo simulation. For a heterogeneous media with a given set of half width of physical parameters in the distribution, one with an oblique misorientation angle near /spl phi//spl sime/15/sup 0/, appears to cause less fluctuation noise spikes and good readout signal. Media with a broad oblique misorientation distribution leads to a correspondingly broad transition width, rough switching curve and noisy signal output.

Analysis of the characteristic dependency of the switching field distribution of a system of noninteracting single domain particles was conducted based on the bi-state, nonequilibrium probabilistic approach. The analysis was carried out as a function of applied field orientations, transition energy barrier variation, and in combination with a given distribution of the particle size and anisotropy constant, under the influence of thermal relaxation. The concept of the blocking temperature that the energy barrier being approximately equal to /spl sim/25 k/sub B/T was shown to be invalid unless the period of the field sweep is /spl sim/1 h.

An exact conformal mapping calculation is carried out, which maps the entire upper edge of an idealized ring head and a symmetric thin-film head in the complex z plane to the real axis of the complex t plane, and uses the slotted-plane approximation to obtain the inverse mapping function t(z). The latter is used to calculate not only the head fields of a given geometry, but also the kernal function to evaluate the total demagnetization field of the interaction head-media system including the media self-demagnetization and the image field induced on the head poles. The total demagnetization field contours for a single-bit arctangent transition and a dibit biquadratic transition corresponding to various head configurations have been obtained and their physical meaning elaborated on. >