Some aspects of overwrite in thick magnetic media

Quantitative comparisons of experiments and the predictions of various models of overwrite phenomena are presented; For the range of wavelengths (λ) 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