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
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!
Sharpening the X-ray view of the nanocosm
23.03.2018 | Changchun Institute of Optics, Fine Mechanics and Physics
Drug or duplicate?
23.03.2018 | Fraunhofer-Institut für Angewandte Festkörperphysik IAF
Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.
The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
23.03.2018 | Event News
19.03.2018 | Event News
16.03.2018 | Event News
23.03.2018 | Materials Sciences
23.03.2018 | Agricultural and Forestry Science
23.03.2018 | Physics and Astronomy