Characteristics of noise in very thin advanced metal particle data storage tapes: an indication of interface roughness

Advanced metal particle magnetic tapes, which have a magnetic top coat on a nonmagnetic under layer, are used for archival applications of data storage. Increasing storage requirements dictate a move to greater bit density which requires smaller particles, higher coercivity and thinner magnetic coatings. This affects the noise characteristics of the tapes and in particular the media contributions. Measurements have shown that for thin magnetic coatings, the magnetic/non-magnetic interface roughness contributes to the noise and can cause an increased saturation noise. This indicates that interface quality is of major importance in producing low noise tapes and may be a limiting factor in future generations of thinner tapes. The dc noise characteristics are also a useful non-destructive indication of interface quality.