Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fridge magnet transformed

15.03.2011
The ubiquitous and unremarkable magnet, BaFe12O19, is manufactured in large volumes, has the simplest crystal structure in its class, and is often seen on refrigerator doors—but it is set for an interesting future.

By substituting a few of its iron atoms with the elements scandium and magnesium, Yusuke Tokunaga and Yoshinori Tokura from the Japan Science and Technology Agency, along with Yasujiro Taguchi from the RIKEN Advanced Science Institute and their colleagues, have produced a very rare magnet[1]. The rarity of the magnet lies in three features that, taken together, endow it with a high degree of tunability.

Firstly, the new magnet is multiferroic: its magnetization and electric polarization are linked, and each can be potentially controlled by both electrical and magnetic fields. Multiferroic materials may allow for magnetic data storage devices that do not require magnetic fields, resulting in reduced cost, power requirements, and bulk. Other applications, such as sensors, may also be possible.

Another feature of this new magnet is that its electronic spins are arranged in a helix (Fig. 1). Therefore the handedness of the helix is a controllable material quantity, along with the material’s magnetic strength and its electric polarization. By applying a magnetic field, the researchers were able to change the geometry of the helix, which in turn increased or decreased the strength of the electric polarization.

The third distinguishing feature is that the material’s spin helix structure persists even above room temperature. This contrasts with many other known multiferroic materials, which require liquid nitrogen temperatures in order to form helical spin structures. In fact, the research team studied BaFe12O19 because a related but more complex magnet demonstrated a helical spin structure at low temperature[2]. It also proved relatively straightforward to fashion large crystals of BaFe12O19, making measurements and device manufacture easier.

The team concluded that the concentration of scandium, the temperature, and the applied magnetic field strength could all be used to control the strength and direction of the materials magnetic and electrical polarization, as well as the retention times of these polarizations. More generally, the new magnet uncovered by Tokunaga, Taguchi, Tokura and colleagues adds to the catalogue of room-temperature multiferroics, which material scientists have just begun to explore. A particularly alluring goal is the discovery of a material with magnetic and electrical ordering at room temperature and in the absence of magnetic field, says Tokunaga.

The corresponding author for this highlight is based at the Cross-Correlated Materials Research Group, RIKEN Advanced Science Institute

Journal information

[1] Tokunaga, Y., Kaneko, Y., Okuyama, D., Ishiwata, S., Arima, T., Wakimoto, S., Kakurai, K., Taguchi, Y. & Tokura, Y. Multiferroic M-type hexaferrites with a room-temperature conical state and magnetically controllable spin helicity. Physical Review Letters 105, 257201 (2010).

[2] Ishiwata, S., Taguchi, Y., Murakawa, H., Onose, Y. & Tokura, Y. Low-magnetic-field control of electric polarization vector in a helimagnet. Science 319, 1643–1646 (2008).

gro-pr | Research asia research news
Further information:
http://www.rikenresearch.riken.jp/eng/research/6543
http://www.researchsea.com

More articles from Materials Sciences:

nachricht Move over, Superman! NIST method sees through concrete to detect early-stage corrosion
27.04.2017 | National Institute of Standards and Technology (NIST)

nachricht Control of molecular motion by metal-plated 3-D printed plastic pieces
27.04.2017 | Ecole Polytechnique Fédérale de Lausanne

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Bare bones: Making bones transparent

27.04.2017 | Life Sciences

Study offers new theoretical approach to describing non-equilibrium phase transitions

27.04.2017 | Physics and Astronomy

From volcano's slope, NASA instrument looks sky high and to the future

27.04.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>