Fujitsu has succeeded in developing a new type of recording media, called LEXIS (Layer Exchange Interaction Stabilized), which has the potential to achieve three times the density of the current theoretical limit governed by thermal fluctuation of magnetization. The new media technology will be used to expand the capacity of hard-disk drives (HDDs) for information storage devices for computers and home information electronics products. Using the new media technology together with a newly developed head, Fujitsu has already demonstrated a recording density of 56Gb/sq. inch — the world’s best performance as of today.

With this density, a 3.5-inch HDD containing two disks could store about 30 movies in DVD-quality video. Moreover, when used together with high-output heads, the new media technology has the potential to achieve a recording density of 300Gb/sq.in. The details of the new media technology will be announced at the International Magnetics Conference in Toronto, Canada, which will take place from April 9. A portion of this technology is based on research sponsored by ASET (the Association of Super-Advanced Electronics Technologies).

Here are some more technical features of the LEXIS technology: The Fujitsu development team was able to reduce information degradation resulting from the media’s thermal decay by adding a multi-layer stabilizing layer under the recording layer. The stabilizing layer does not affect information output, and by firmly coupling magnetically with the recording layer (anti-ferromagnetic coupling) it stabilizes recording signals from degradation, even at higher recording density. — As a result of this technology, degradation of recorded information by thermal decay can be reduced to one fifth of current levels. — With a prototype media using this technology and specular GMR (giant-magneto-resistive) head now under development, Fujitsu researchers have demonstrated 56 Gb/sq.in. recording density – a world record. This level of density is equivalent to 78 gigabytes (627 Gbits) on a single 3.5 disk.

The density limit imposed by thermal decay in existing media has been estimated at 100 Gb/sq.in. Since media utilizing this new technology is able to accommodate three times more magnetic energy than the present media, it has potential to realize recording density of 300 Gb/sq.inch when combined with a high-output head, such as a TMR (Tunneling Magneto-Resistive) head.