Effects of structure on noise in very thin particulate data storage media

The effects of structure on noise in very thin particulate data storage tapes have been investigated using DC and tone-noise methods. The results from a set of five commercial development tapes indicate that large structural correlations of size ∼5 μm become increasingly apparent as the magnetic layer of the tapes becomes thinner over the range 140-50 nm. As the samples were fabricated from identical particles (MP4 length ∼60 nm) using the same double-coating process, and with the tone-noise results showing comparable top surface roughness, these findings are consistent with large in-plane structures at the magnetic/non-magnetic interface that may be expected from mixing effects during production drying. Since this interface moves ever closer to the head with increasing data density, its effects on media noise will become increasingly important.