Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Spin structure reveals key to new forms of digital storage, study shows

11.06.2012
A synthetic compound long known to exhibit interesting transition properties may hold the key to new, non-magnetic forms of information storage, say researchers at the RIKEN SPring-8 Center and their collaborators. The team's latest findings shed light on the complex relationship between a compound's electron spin arrangement and its transport properties, an area researchers have long struggled to understand.

Crystal structure of Cd2Os2O7The metal-insulator transition (MIT) is a phenomenon in which certain (electricity-conducting) metals make a sudden transition to become a (non-conducting) insulator when cooled below a given temperature. Unlike pure insulators such as silicon and germanium, and pure conductors such as gold and silver, metals with MITs are by their nature unstable and difficult to characterize. This instability is also their strength: complex materials with MITs such as semiconductors form the building blocks for much of our modern technology.

Elucidating the physical basis for MIT, one of the oldest and least well-understood phenomena in condensed matter physics, would shed light on the electron transport properties of a wide range of potentially useful materials. Among these materials, the compound Cd2Os2O7, first discovered more than 30 years ago, has recently attracted renewed attention. Cd2Os2O7 has the intriguing property that when cooled to 227K (-46 °C), it undergoes both a metal-insulator transition and a magnetic transition to a state in which all its electron spins are aligned. This spin alignment, which makes the material magnetic, is useful for a wide array of applications, notably information storage.

Previous efforts to elucidate this magnetic structure, however, have been complicated by another property of Cd2Os2O7: its propensity to absorb neutrons, which interferes with standard neutron scattering techniques used to analyze magnetism. To get around this problem, the researchers employed an alternative technique known as resonant x-ray scattering (RXS) using synchrotron radiation from the RIKEN SPring-8 facility, the world's most powerful synchrotron light source. Their results show that at 227K, Cd2Os2O7 structures itself into a tetrahedral network of osmium atoms with electron spins in each tetrahedron pointing in one of two directions: all inward, or all outward (Figure 1). The structure of this unusual "all-in-all-out" arrangement is such that the spins cancel each other out, so that the material as a whole is not magnetic.

Cd2Os2O7 thus has all the makings of a new kind of information storage medium, one whose binary bits of information ("all-in" and "all-out" spin arrangements) would, unlike present-day computer memory, be largely unaffected by surrounding magnetic fields. The results also provide fundamental insights into how electron spin can influence a material's transport properties, with broad applications in condensed matter physics.

For more information, please contact
Takahisa Arima
Spin Order Research Team
Photon Science Research Division
RIKEN SPring-8 Center
Global Relations Office
RIKEN
Tel: +81-(0)48-462-1225 / Fax: +81-(0)48-463-3687
Mail: koho@riken.jp
Page Top
Reference:
J. Yamaura, K. Ohgushi, H. Ohsumi, T. Hasegawa, I. Yamauchi, K. Sugimoto, S. Takeshita, A. Tokuda, M. Takata, M. Udagawa, M. Takigawa, H. Harima, T. Arima, and Z. Hiroi. "Tetrahedral Magnetic Order and the Metal-Insulator Transition in the Pyrochlore Lattice of Cd2Os2O7." Physical Review Letters (2012).

About RIKEN

RIKEN is Japan's flagship research institute devoted to basic and applied research. Over 2500 papers by RIKEN researchers are published every year in reputable scientific and technical journals, covering topics ranging across a broad spectrum of disciplines including physics, chemistry, biology, medical science and engineering. RIKEN's advanced research environment and strong emphasis on interdisciplinary collaboration has earned itself an unparalleled reputation for scientific excellence in Japan and around the world.

About the RIKEN SPring-8 Center

The RIKEN SPring-8 Center, located in Harima, Japan, is home to SPring-8 (the Super Photon ring-8 GeV), the most powerful synchrotron radiation facility in the world. The RIKEN SPring-8 Center was established to support frontier research initiatives applying SPring-8's unique radiation to a wide variety of fields, notably structural biology and materials science. The center also focuses on the development of technology for producing high-quality synchrotron radiation sources and on development of the new SACLA X-ray Free Electron Laser project.

RIKEN Global Relations Office | EurekAlert!
Further information:
http://www.riken.jp/engn/r-world/info/release/press/2012/120524/index.html

More articles from Physics and Astronomy:

nachricht Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences

nachricht Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication
16.07.2018 | Chinese Academy of Sciences Headquarters

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: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>