Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Transition from 3 to 2 dimensions increases conduction, MIPT scientists discover

07.07.2015

Scientists from the MIPT Department of Molecular and Chemical Physics have for the first time described the behavior of electrons in a previously unstudied analogue of graphene, two-dimensional niobium telluride, and, in the process, uncovered the nature of two-dimensionality effects on conducting properties. These findings will help in the creation of future flat and flexible electronic devices.

In recent decades, physicists have been actively studying so-called two-dimensional materials. Andrei Geim and Konstantin Novoselov received the Nobel Prize for their research on graphene, the most well-known among them.


This is the crystal structure of Nb3SiTe6.

Credit: © J. Hu et al/ Nature Physics

The properties of such materials, which can be described as "sheets" with a thickness of a few atoms, strongly differ from their three-dimensional analogues. For example, graphene is transparent, conducts current better than copper and has good thermal conductivity. Scientists believe that other types of two-dimensional materials may possess even more exotic properties.

A group of scientists from Russia and the USA, including Pavel Sorokin and Liubov Antipina from MIPT, recently conducted research on the properties of the crystals of one such material,Nb3SiTe6, a compound of niobium telluride.

In their structure, the crystals resemble sandwiches with a thickness of three atoms (around 4 angstroms): a layer of tellurium, a layer of niobium mixed with silicon atoms and then another layer of tellurium. This substance belongs to a class of materials known as dichalcogenides, which many scientists view as promising two-dimensional semiconductors.

The scientists synthesized Nb3SiTe6 crystals in a laboratory at Tulane University (New Orleans). They then separated them into two-dimensional layers, taking samples for further analysis by transmission electron microscopy, X-ray crystal analysis and other methods. The goal of the researchers was to investigate electron-phonon interaction changes in two-dimensional substances.

Quasi particles, quanta of crystal lattice oscillations, are called phonons. Physicists introduced the concept of phonons because it helped simplify the description of processes in crystals, and tracking of electron-phonon interaction is fundamentally important for description of the different conducting properties in matter.

"We developed a theory that predicts that electron-phonon interaction is suppressed due to dimensional effects in two-dimensional material. In other words, these materials obstruct the flow of electrons to a lesser extent," says Pavel Sorokin, a co-author of the study, doctor of physical and mathematical sciences, and lecturer at the MIPT Section of the Physics and Chemistry of Nanostructures (DMCP).

American colleagues confirmed this predictioninrelatedexperiments. "They conducted measurements where the same effectwas observed. Our calculations allowed the ruling out of other explanations; we managed to prove that changes in electron-phonon interaction occur specifically because of the two-dimensionality of the membrane," Sorokin adds.

Full details of the research discussed above can be found in an article published in the journal Nature Physics (DOI:10.1038/NPHYS3321).

Media Contact

Stanislav Goryachev
stas.goryachev@gmail.com
7-964-501-2307

 @phystech

http://mipt.ru/en/ 

Stanislav Goryachev | EurekAlert!

More articles from Physics and Astronomy:

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
17.07.2018 | Forschungsverbund Berlin

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

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

Microscopic trampoline may help create networks of quantum computers

17.07.2018 | Information Technology

In borophene, boundaries are no barrier

17.07.2018 | Materials Sciences

The role of Sodium for the Enhancement of Solar Cells

17.07.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>