Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A clearer view of a hot technique

06.11.2014

A multifunctional testing instrument helps improve production of laser-heated hard disk drives with enhanced storage capacities

Today’s hard disk drives can hold terabytes of digital data, but manufacturers are having trouble squeezing more storage capacity into these devices using conventional procedures. Now, a new technique that promises to solve this impasse — heat-assisted magnetic recording (HAMR) — can be integrated more efficiently into future hard drives thanks to an analytical tool developed by A*STAR researchers (1).


An advanced testing instrument can measure laser-driven changes to magnetic disk drives with impressive spatial precision.

© ktsimage/iStock/Thinkstock

Data-storing ‘bits’ inside hard disk drives have to be turned on and off with magnetic fields. But as bit sizes diminish to improve storage density, the recording heads need stronger and stronger fields to resolve individual magnetic grains. Eventually, impractically large fields are required to read and write data.

The HAMR approach uses a small laser mounted on the disk recording head to heat up the magnetic material before writing to it. The increase in temperature reduces the magnetic field intensity necessary for data storage and consequently, smaller bit sizes can be used. Rapid cooling of the magnetic grains ensures the stability of the freshly recorded data.

Researchers are confident that the HAMR technique can lead to 20-terabyte hard drives within a few years if some specific challenges can be overcome. One current problem is that accurately testing the temperature-dependent recording in localized regions is difficult. Typical analytical methods have to heat up relatively large sample volumes, a time-consuming process that can irreversibly damage HAMR media.

Hongzhi Yang, with a team from the A*STAR Data Storage Institute and the National University of Singapore designed an improved ‘pump–probe’ laser device to scrutinize HAMR devices. The instrument uses an initial intense beam to heat up a localized region of the magnetic disk.

Then, a weaker laser probes the heated region for the micro-magneto-optic Kerr effect (μ-MOKE), a phenomenon that can gauge a material’s magnetization state.

By repeating these measurements with different heating beam conditions, the researchers obtained detailed data on HAMR writing, reading and magnetic states from specific microscopic spots on the hard drive surface — information currently unavailable through other techniques.

“The challenge in developing this testing instrument was integrating the complex optical and mechanical components to achieve good signal-to-noise ratios and uniform temperature distribution in the media during heating,” says Yang. “But compared to traditional bulk-heating techniques, our method is much faster, allows full disk measurement and avoids annealing effects.”

The team is confident that this instrument can be incorporated into disk drive manufacturing plants as HAMR captures a larger share of magnetic recording technology.

Reference
Yang, H. Z., Chen, Y. J., Leong, S. H., An, C. W., Ye, K. D. et al. A multi-functional testing instrument for heat assisted magnetic recording media. Journal of Applied Physics 115, 17B726 (2014).


Associated links
A*STAR article

A*STAR Research | ResearchSEA
Further information:
http://www.researchsea.com

More articles from Physics and Astronomy:

nachricht Prediction: More gas-giants will be found orbiting Sun-like stars
22.02.2017 | Carnegie Institution for Science

nachricht NASA's fermi finds possible dark matter ties in andromeda galaxy
22.02.2017 | NASA/Goddard Space Flight Center

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

Scientists unlock ability to generate new sensory hair cells

22.02.2017 | Life Sciences

Prediction: More gas-giants will be found orbiting Sun-like stars

22.02.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>