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 Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously
17.01.2017 | Sonderforschungsbereich 668

nachricht Manchester scientists tie the tightest knot ever achieved
13.01.2017 | University of Manchester

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>