Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Data storage: Making the switch

24.06.2013
Magnetic materials that change their properties when heated could pack more data on to hard drives
A ‘sandwich’ of three iron alloy layers could help to create computer hard drives that can store more data than ever before. Tiejun Zhou and co-workers at the A*STAR Data Storage Institute in Singapore expect that their development, based on a new technology called heat-assisted magnetic recording (HAMR), could boost the capacity of disks.

Conventional hard drives contain a tiny electromagnet — a write head — that hovers over a spinning disk coated with a ferromagnetic material. The electromagnet induces the magnetic field within small regions of the disk to point either up or down, encoding one bit of data.

Heat can jumble these magnetic bits and destroy the data. The latest disks use materials with a very large coercivity — a measure of how difficult they are to demagnetize. However, write heads must exert even greater magnetic fields to encode data in such materials. The balance between bit size, coercivity and the electromagnet's strength ultimately puts an upper limit on disk density of about 1 terabit per square inch.

In HAMR systems, each recording region is briefly heated above its Curie temperature, a point when magnetic coercivity drops significantly and a much smaller field can write the bit. Once the region cools, the coercivity rises and the bit locks into place.

Zhou’s team found a way to reduce both the writing temperature and the switching field in HAMR systems. The upper iron–platinum layer of the sandwich stores data bits; the lower iron–cobalt layer helps to channel the write-head’s magnetic field, enabling data writing; and the middle iron–rhodium layer acts as a switch between the two. The middle layer is antiferromagnetic at room temperature so blocks any magnetic coupling between the other layers. At about 350 kelvin, however, it becomes ferromagnetic, allowing the layers to couple.

Iron–platinum normally has a Curie temperature of about 750 kelvin, but that plummets when coupled to the iron–cobalt layer. Data can therefore be written to the iron–platinum layer once the iron–rhodium layer becomes ferromagnetic, at about 350 kelvin.

Coupling also reduces the coercivity of the iron–platinum layer, so a write head would need only to generate one-third of the usual magnetic field to encode a bit. “Theoretically, the bit can occupy a space as small as 100 square nanometers,” says Zhou. The team now plans to reduce the size of the nanocrystals in each data region of the iron–platinum layer, while maintaining its high coercivity.

The A*STAR-affiliated researchers contributing to this research are from the Data Storage Institute

A three-layer sandwich of magnetic materials could help to pack more data on to hard drives.

© Zoonar/Thinkstock

Journal information

Zhou, T. J., Cher, K., Hu, J. F., Yuan, Z. M. & Liu, B. The concept and fabrication of exchange switchable trilayer of FePt/FeRh/FeCo with reduced switching field. Journal of Applied Physics 111, 07C116 (2012).

A*STAR Research | Research asia research news
Further information:
http://www.research.a-star.edu.sg/research/6688
http://www.researchsea.com

More articles from Materials Sciences:

nachricht Reliable molecular toggle switch developed
30.03.2017 | Karlsruher Institut für Technologie (KIT)

nachricht Researchers shoot for success with simulations of laser pulse-material interactions
29.03.2017 | DOE/Oak Ridge National Laboratory

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

'On-off switch' brings researchers a step closer to potential HIV vaccine

30.03.2017 | Health and Medicine

Penn studies find promise for innovations in liquid biopsies

30.03.2017 | Health and Medicine

An LED-based device for imaging radiation induced skin damage

30.03.2017 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>