Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Vortices get organized

28.02.2011
Exotic entities that arrange into a crystalline structure at near room-temperature could lead to a new approach to electronic memory

A crystal consisting not of atoms but exotic swirling magnetic entities, called skyrmions, has been identified at near room-temperature by Yoshinori Tokura of the RIKEN Advanced Science Institute, Wako, and his colleagues from several other institutes in Japan[1].

Previous observations of a skyrmion crystal state, in transition-metal–silicide materials, have been at cryogenic temperatures below 40 kelvin. The existence of skyrmions at room temperature improves the practicality of harnessing their potential for use in novel computer memories.

Skyrmions are formed on some surfaces when the spins of the electrons—think of an arrow about which each electron rotates—collectively arrange such that they wrap around the surface of a sphere (Fig. 1). This pattern spirals in such a way that the spins on the outside point up whereas those at the core point down. This collection of spins can display many properties associated with a single particle. “A skyrmion crystal is the periodic array of these particle-like entities,” explains Tokura.

Earlier neutron-scattering experiments by other researchers identified this unusual effect in both iron–cobalt silicide and manganese silicide. Tokura and his team, however, investigated skyrmions in iron germanium. This alloy has the same cubic atomic crystal structure as iron–cobalt silicide and manganese silicide—the two materials in which skyrmions have been observed at low temperatures; but it remains in the necessary magnetic structure up to a much higher temperature.

Using a transmission electron microscope, the researchers probed the magnetization on the surface of polished layers of the iron–germanium alloy. They found tell-tale signs of skyrmions at temperatures up to 260 kelvin, particularly when they applied a small magnetic field perpendicularly to the surface.

This material also provides an excellent opportunity to investigate the stability of the skyrmion crystal, the team notes. Previous studies focused on very thin layers of material. Tokura and his team investigated the influence of film thickness and found that for thicknesses greater than the distance between skyrmions, about 75 nanometers in this case, the skyrmion crystal state is suppressed and a more conventional ferromagnetic phase starts to dominate.

Skyrmions could play an important role in the development of spintronics—using electron spin to carry information in the same way that electron charge is used in conventional electronics. “Skyrmion crystals could also be applied in memory and logic devices,” says Tokura. The advantage over conventional systems is that control is achieved using electric, rather than magnetic fields, which is known to be more efficient.

The corresponding author for this highlight is based at the Emergent Materials Department, RIKEN Advanced Science Institute

Journal information

[1] Yu, X.Z., Kanazawa, N., Onose, Y., Kimoto, K., Zhang, W.Z., Ishiwata, S., Matsui, Y. & Tokura, Y. Near room-temperature formation of a skyrmion crystal in thin-films of the helimagnet FeGe. Nature Materials 10, 106–109 (2011).

gro-pr | Research asia research news
Further information:
http://www.rikenresearch.riken.jp/eng/research/6527
http://www.researchsea.com

More articles from Materials Sciences:

nachricht Serendipity uncovers borophene's potential
23.02.2017 | Northwestern University

nachricht Switched-on DNA
20.02.2017 | Arizona State University

All articles from Materials Sciences >>>

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

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>