An analysis of recording demagnetization

Current investigators are devoting considerable effort to the analysis of self- and adjacent bit demagnetization. However, it is shown in this paper that recording demagnetization degrades and limits digital recording to a greater extent than any other factor. Recording demagnetization reflected in the nonlinearity of the write process is the prime cause of pulse asymmetry. The nonlinear head field contour distribution results in the magnetization discontinuity in the transition zone being asymmetrical and becoming more asymmetrical as the write current increases beyond saturation. At high bit densities, recording demagnetization becomes so severe that only transition zones are recorded on the media, leading to a sinusoidal magnetization distribution. It is also shown that the manufacturing process of particulate media can introduce several adverse conditions which will affect recording demagnetization.