Quantitative comparisons of experiments and the predictions of various models of overwrite phenomena are presented; For the range of wavelengths (/spl lambda/) and write current amplitudes (I) used in this work we find that the residual signals present after overwrite can be described within the context of a single physical process which is described in the rewriting model. The rewriting model is found to give rise to both the overwrite induced bit-shift, and the depth-of-recording phenomena which we observe. The experimental results indicate that variations in the head properties (efficiency and head field gradient) do not contribute significantly to the residual signals following overwrite, for the head and frequency range we used. Finally, we present the first spatial-domain measurements of spatial phase sensitive overwrite induced bit-shift in thick media.

Measurements of the recorded output signal at fixed recording wavelength, as a function of the magnetic field (H-g) over an inductive head gap, are reported for several magnetic recording media. For a given tape, comparisons of the output measured with different relative head-to-tape speeds and different frequencies for the fundamental component of the square wave write current, but at fixed recording wavelength and H-g, are used to probe experimentally the validity of treating the recording process in magnetic media as being effectively static. The results support the static approximation for the recording process for the range of frequencies currently employed in magnetic recording systems.