Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Lead islands in a sea of graphene magnetize the material of the future

15.12.2014

Researchers in Spain have discovered that if lead atoms are intercalated on a graphene sheet, a powerful magnetic field is generated by the interaction of the electrons' spin with their orbital movement.

This property could have implications in spintronics, an emerging technology promoted by the European Union to create advanced computational systems.


In the sea of graphene (over an iridium crystal), electrons' spin-orbit interaction is much lower than that created by intercalating a lead island.

Credit: IMDEA Nanoscience/UAM/ICMM-CSIC/UPV-EHU

Graphene is considered the material of the future due to its extraordinary optical and electronic mechanical properties, especially because it conducts electrons very quickly. However, it does not have magnetic properties, and thus no method has been found to manipulate these electrons or any of their properties to use it in new magnetoelectronic devices, although Spanish scientists have come upon a key.

Researchers from IMDEA Nanoscience, the Autonomous University of Madrid, the Madrid Institute of Materials Science (CSIC) and the University of the Basque Country describe in the journal Nature Physics this week how to create a powerful magnetic field using this new material.

The secret is to intercalate atoms or Pb islands below the sea of hexagons of carbon that make up graphene. This produces an enormous interaction between two electron characteristics: their spin - a small 'magnet' linked to their rotation - and their orbit, the movement they follow around the nucleus.

"This spin-orbit interaction is a million times more intense than that inherent to graphene, which is why we obtain revolutions that could have important uses, for example in data storage," explains Rodolfo Miranda, Director of IMDEA Nanoscience and head of the study.

To obtain this effect, the scientists laid a layer of lead on another of graphene, in turn grown over an iridium crystal. In this configuration the lead forms 'islands' below the graphene and the electrons of this two-dimensional material behave as if in the presence of a colossal 80-tesla magnetic field, which facilitates the selective control of the flow of spins.

Traffic control with two lanes

"And, what is most important, under these conditions certain electronic states are topologically protected; in other words, they are immune to defects, impurities or geometric disturbances," continues Miranda, who gives this example: "If we compare it to traffic, in a traditional spintronic material cars circulate along a single-lane road, which make collisions more likely, whilst with this new material we have traffic control with two spatially separate lanes, preventing crashes."

Spintronics is a new technology that uses electrons' magnetic spin to store information bits. It arose with the discovery of giant magnetoresistance, a finding which won Peter Grümberg and Albert Fert the Nobel Prize in Physics in 2007. It is an effect that causes great changes to the electric resistance of fine multi-layer materials and has led to the development of components as varied as the reader heads on hard disks or the sensors in airbags.

The first generation of spintronic or magnetoresistant devices was based on the effect magnetic materials have on electron spin. But a second generation is already up and running, and encompasses this new study, in which electrons' own spin-orbit interaction acts on them as if there were a real external magnetic field, even if there is not.

The use of graphene as an active component in spintronics is one of the fundamental aims of the large European Union project 'Graphene Flagship'. The scientists' final objective is to wilfully control the type of spin the electrons in this new material have in order to apply it to the electronic devices of the future.

References

Fabian Calleja, Héctor Ochoa, Manuela Garnica, Sara Barja, Juan Jesús Navarro, Andrés Black, Mikhail M. Otrokov, Evgueni V. Chulkov, Andrés Arnau, Amadeo L. Vázquez de Parga, Francisco Guinea, Rodolfo Miranda. "Spatial variation of a giant spin-orbit effect induces electron confinement in graphene on Pb islands". Nature Physics, 15 December 2014.

SINC | EurekAlert!
Further information:
http://www.fecyt.es/fecyt/home.do

Further reports about: Electrons European IMDEA Nanoscience Nature Physics graphene magnetic field materials physics spintronics

More articles from Materials Sciences:

nachricht Decoding cement's shape promises greener concrete
08.12.2016 | Rice University

nachricht Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D
08.12.2016 | DOE/Brookhaven 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: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>