17 Gb/in/sup 2/ areal density demonstration at 214 Mb/s

Magnetic recording demonstration over 100 Gb/in/sup 2/

“…Nonlinear distortion does not seem to be significant in our measurement [14]. Compared to the previous demonstration at lower areal densities [2], we found that the dc erased media noise has become more significant. This could be due to the shrinking particle size and improved grain segregation that make the media more of a particulate nature than of a coupled thin film nature.…”

“…Very high efficiency is obtained by using a yoke length of less than 15 m and just four coil turns. Eddy currents in the yoke are damped by using a layer of high-resistivity NiFe in the shared pole as described previously [2] to further improve efficiency. Sharp field gradients are obtained by milling through the top pole to form trenches in the writer gap and a portion of the shared pole to a depth of twice the writer gap length.…”

Recent advances in the recording physics of thin-film media

“…The onset of super-paramagnetism presumably represents the greatest challenge that magnetic recording ever has experienced. Recently, several areal density demonstrations have reported areal densities of more than 10 Gbit inch −2 [1,2,108]. In these demonstrations, not only the recording density, but also the stability of the recorded information was considered.…”

“…In fact, there have been numerous examples in the literature over the last 40 years, postulating that magnetic recording has reached its limit. Today, recording demonstrations, as well as commercial storage devices, have exceeded these 'limits', proving that many of the previous considerations on limits of magnetic recording have simply been wrong [1,2].…”