Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How to make the wonder material graphene superconducting

12.02.2014
Whenever a new material is discovered, scientists are eager to find out whether or not it can be superconducting.

This applies particularly to the wonder material graphene. Now, an international team around researchers at the University of Vienna unveiled the superconducting pairing mechanism in Calcium doped graphene using the ARPES method. Their results are published in the reputed journal Nature Communications.


This image shows ARPES measurements of Calcium doped graphene. Left: the Fermi surface of graphene (top) and the Dirac cone (bottom). Right: The kink in the spectral function in the two crystallographic main directions. The scientists analyzed the strength of the kink in order to estimate the superconducting critical temperature.

Credit: Copyright: A. Grüneis and A.V. Fedorov

Superconducting materials exhibit an invaluable feature when cooled below a critical temperature – they allow the transport of an electric current without loss. Superconductivity is based on the fact that in certain materials electrons can pair up which – at a higher temperature – would otherwise repel each other. Scientists from the Electronic Properties of Materials Group at the Faculty of Physics (University of Vienna) and their collaboration partners teamed up to uncover the potential superconducting coupling mechanism of the wonder material graphene.

Graphene, a single-atom thick layer of carbon atoms was discovered in 2004 and is regarded as one of the most amazing and versatile substances available to mankind. The impact of the first real two-dimensional material is so significant that a Nobel Prize was awarded for its discovery. Until recently, there were no experimental reports of superconductivity in graphene although its close relatives, graphite and fullerenes can be made superconducting by intentionally introducing electrons in the material (doping).

The ARPES method – how light sheds light on superconductivity

In order to shed light on superconductivity in graphene, the scientists resorted to the powerful photoemission method: when a light particle interacts with a material it can transfer all its energy to an electron inside that material. If the energy of the light is sufficiently large, the electron acquires enough energy to escape from the material. Determining the angle under which the electrons escape from the material enables the scientists to extract valuable information on the electronic properties and the complex many-body interactions of the material.

Nikolay Verbitskiy and Alexander Grüneis from the University of Vienna together with Alexander Fedorov and Denis Vyalikh from IFW-Dresden and TU-Dresden and Danny Haberer from the University of California at Berkeley and their colleagues employed this technique – the so-called Angle-resolved photoemission spectroscopy (ARPES) – at the Elettra synchrotron in Trieste where they researched the interaction of a series of electron dopants (Cs, Rb, K, Na, Li, Ca) with monolayer graphene.

Who makes the grade?

According to the findings of the scientists, calcium is the most promising candidate to induce superconductivity in graphene with a critical temperature of about 1.5K. This critical temperature is rather low compared to e.g. fullerenes which superconduct at 33K. However, graphene offers several huge advantages over many other materials. Since it consists only of carbon atoms arranged in single layers, it is easy to be chemically functionalized. Moreover, it can be grown in multiple numbers of atom layers in various stacking orders and can be doped in several different ways. Thereby, it gives a multitude of options to experiment with.

The scientists are confident that, while graphene will not set new record critical temperatures, the ease by which its properties can be modified will enhance our understanding of superconductivity in general and carbon materials in particular.

Publication:

Observation of a universal donor-dependent vibrational mode in grapheme: A.V. Fedorov, N.I. Verbitskiy, D. Haberer, C. Struzzi, L. Petaccia, D. Usachov, O.Y. Vilkov, D.V. Vyalikh, J. Fink, M. Knupfer, B. Büchner & A. Grüneis. Nature Communications | 5:3257 | DOI: 10.1038/ncomms4257.

Alexander Grüneis | EurekAlert!
Further information:
http://www.univie.ac.at/

More articles from Materials Sciences:

nachricht Breaking bad metals with neutrons
16.01.2018 | DOE/Argonne National Laboratory

nachricht White graphene makes ceramics multifunctional
16.01.2018 | Rice 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: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Novel chip-based gene expression tool analyzes RNA quickly and accurately

18.01.2018 | Medical Engineering

Scientists on the road to discovering impact of urban road dust

18.01.2018 | Ecology, The Environment and Conservation

Gran Chaco: Biodiversity at High Risk

17.01.2018 | Ecology, The Environment and Conservation

VideoLinks
B2B-VideoLinks
More VideoLinks >>>