Reducing information stored in magnetic thin films to the size of single grains could improve computer hard drives

October 24, 2012
Even more data is set to be packed into the magnetic thin films of computer hard drives, thanks to modeling research at A*STAR. Credit: Stockbyte/Thinkstock

Despite the increasing competition from alternative technologies such as solid-state drives, magnetic disks remain an important data-storage technology. They are not only reliable and inexpensive, but their storage density has potential for even further improvement. One method under current investigation is storing each data bit in a single magnetic grain of the thin film of the recording medium, rather than in several grains as in conventional hard drives. Storage in single grains only would increase stability and reduce the magnetic fields required to write bits.

By modeling write processes in hard disks, Melissa Chua and her co-workers at the A*STAR Data Storage Institute, Singapore, have demonstrated how this is possible in practice. "The hope is that such a grain-based magnetic recording can extend storage densities by an order of magnitude, to achieve ten terabits per square inch," she says.

Thin magnetic films for data storage coat the top layer of plastic films in hard-disk drives and consist of many neighboring nanometer-sized grains. As of magnetic films has increased over the years, the surface area used for storage per bit is now comparable to the size of these grains.

Achieving single-grain storage requires a solid understanding of the write processes. Two theoretical models are available to describe these processes. One is an analytical model that uses a simplified description of the magnetic fields within the grains and within the write head of the hard disk. This model achieves fast and easy-to-implement modeling of the recording process, Chua notes.

The second model is a that uses tabulated values of parameters that detail the switching process when information is written to the hard disk. These parameters are derived from detailed simulations of the magnetic fields in the grains and from the write head. From these, the researchers produced a probability for a grain to switch under given circumstances. This detailed approach is more accurate, but also more time intensive than the analytical approach.

Chua and her co-workers successfully applied both models to the grain-based storage process. They simulated the switching of single grains with both methods and then compared their individual performance. By adjusting relevant process parameters for both models, they achieved good agreement between them. Having shown the suitability of both models, choosing which model to use depends on specifics, such as the desired accuracy. Either way, Chua says, "Both models enable the system-level testing of future technologies."

Explore further: Packing in six times more storage density with the help of table salt

More information: Chua, M., Elidrissi, M. R., Eason, K., Zhang, S. H., Qin, Z. L. et al. Comparing analytical, micromagnetic and statistical channel models at 4 Tcbpsi patterned media recording. IEEE Transactions on Magnetics 48, 1826–1832 (2012). ieeexplore.ieee.org/xpl/articl … urnals+%26+Magazines

Related Stories

TDK sees hard drive breakthrough in areal density

October 3, 2012

(Phys.org)—TDK has realized increased areal density of its hard disk drives. TDK has set a new record, compared to previous areal density at 1Tbit/inch2, with the new stat of increased density to 1.5Tbits/inch2. The point ...

Nanospheres stretch limits of hard disk storage

June 15, 2010

(PhysOrg.com) -- A new magnetic recording medium made up of tiny nanospheres has been devised by European researchers. The technology may lead to hard disks able to store more than a thousand billion bits of information in ...

Recommended for you

Two teams independently test Tomonaga–Luttinger theory

October 20, 2017

(Phys.org)—Two teams of researchers working independently of one another have found ways to test aspects of the Tomonaga–Luttinger theory that describes interacting quantum particles in 1-D ensembles in a Tomonaga–Luttinger ...

Using optical chaos to control the momentum of light

October 19, 2017

Integrated photonic circuits, which rely on light rather than electrons to move information, promise to revolutionize communications, sensing and data processing. But controlling and moving light poses serious challenges. ...

Black butterfly wings offer a model for better solar cells

October 19, 2017

(Phys.org)—A team of researchers with California Institute of Technology and the Karlsruh Institute of Technology has improved the efficiency of thin film solar cells by mimicking the architecture of rose butterfly wings. ...

Terahertz spectroscopy goes nano

October 19, 2017

Brown University researchers have demonstrated a way to bring a powerful form of spectroscopy—a technique used to study a wide variety of materials—into the nano-world.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.