CONTEXT

Magnetic recording on hard drive disk remains the best choice for reading and writing large quantities of information because it combines high density and low cost. Storage densities are still increasing at a rate of 100% a year and densities of 400Gbit/in are already obtained in laboratories. This increase is limited by the thermal instability of the information which appears as the grains of the magnetic layer become too small (the “superparamagnetic limit”). Different solutions have been studied to overcome this limitation.

TECHNICAL DESCRIPTION

One of the most promising solution is the use of patterned media where one magnetic structure defines one bit of information. However intrinsic problems are limiting their industrial use: the high coercivities and the very large distribution of the switching fields of the bits, both mostly due to the patterning.

The invention is based on the idea of storing information on a non-patterned continuous layer (it didn’t suffer from any modification or damages) and on confining the information bit by the stray field from a nanometric magnetic structure defined above or below this continuous layer. If the switching fields are very dependant from the patterning, the dipolar stray fields are not because there are proportional to the magnetization and so to the surface. Then the switching fields distribution is strongly reduced compare to the conventional approach. One example of the medias described in the invention is shown in the figure.

BENEFITS

– Storage density.

– Compatible with all the fabrication processes that have been developed for reaching the ultra-high storage densities (1Tbit/in²) with the patterned medias.

INDUSTRIAL APPLICATIONS

– Data Storage

DEVELOPMENT STAGE

Prototypes are available.

For further information, please contact us (Ref 01580-01)