Spatial effects in the dc modulation noise of advanced MP tape

An experimental study of dc modulation noise as a function of the remanent magnetized state has been made for a set of advanced metal particle tapes with identical particles but different magnetic coating thickness between 150 and 300 nm. The thickest tape showed noise characteristics similar to conventional thick tapes, whilst the noise spectrum of the thinnest was "thin-film" like. A simulation of a magnetic recording head-read process has been developed and applied to a model of particulate recording media. This showed that particles at the surface contribute noise characteristics similar with those of thin films, whereas noise from particles in the bulk is characteristic of thick media. As tapes get thinner, the noise is dominated by the characteristics of the particles on the top surface.