Thursday, July 09, 2009

Memory Densities About to Go Up?

Researches at the Leibniz Institute for Solid State and Materials Research, in Dresden, Germany headed up by Ruijuan Xiao say they found a way to increase storage capacity of magnetic data drives by a factor of 1,000. While the finding is simply a theory, the answer lies in tying cobalt molecules to a ring of carbon, as cobalt has the highest magnetic anisotropy energy (MAE) of all ferromagnetic elements suitable for storage. The density of data storage depends on the size of magnetic grains, which cannot be shrunk indefinitely.

MAE is related to how easy it is to flip the magnetic field from one direction to the other, with a reliable lifespan of about 10 years for current hard drives. Today's high-end cobalt drives have about 50,000 atoms in a hexagonal close-packed structure, which results in an MAE of 0.06 meV per atom. Without changing this arrangement, which is necessary for reliable, long-term data storage, it is said to be possible to reduce the size of the cobalt grains to 15,000 atoms.

Xiao and his researchers say they have found a way to trick cobalt dimers, or two identical simple molecules, to think they're in a hexagonal close structure by attaching of them to a hexagonal carbon ring such as benzene or graphene.

The magnetic field between the cobalt atoms can then be switched by applying a weak magnetic field along with a strong electric field. Cobalt's MAE is 100 meV, which is reduced when the element is chemically bonded, but Xiao says his method of bonding it to carbon hexagons does not have such an effect.

Apart from longer life, this finding, if proven true with a working prototype, could also result in higher memory density, as current cobalt grains used in magnetic storage are about 8nm in width. Benzene rings, in comparison, are just 0.5nm wide. [via TechnologyReview]

Three hurdles to go. One functional prototype. Then a product unit (scaling and reproducibility issues as well as cost effectiveness). Then getting it adopted. That last is harder than it seems. There was a company during the dotcom days that came up with some CD/DVD replacement tech that was amazing for its time (TB+ sized disks), but...didn't get anywhere due to not being able to get someone to adopt it.

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