Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanoscale Friction: High Energy Losses in the Vicinity of Charge Density Waves

16.12.2013
In collaboration with the University of Basel, an international team of researchers has observed a strong energy loss caused by frictional effects in the vicinity of charge density waves.

This may have practical significance in the control of nanoscale friction. The results have been published in the scientific journal Nature Materials.


An oscillating Atomic Force Microscope tip in proximity to the Charge Density Wave (CDW) on NbSe2 surface. The yellow and blue spheres are the Selenium and Niobium atoms forming the lattice.

University of Basel

Friction is often seen as an adverse phenomenon that leads to wear and causes energy loss. Conversely, however, too little friction can be a disadvantage as well – for example, running on an icy surface or driving on a wet road.

An understanding of frictional effects is therefore of great importance – particularly in the field of nanotechnology, where friction has to be controlled at a nanoscale. A recent study conducted by researchers from the University of Basel, the University of Warwick, the CNR Institute SPIN in Genoa and the International Centre for Theoretical Physics (ICTP) in Trieste has helped to give a better understanding of how friction works in microscopic dimensions.

In the experiment led by Prof. Dr. Ernst Meyer, Professor of Experimental Physics at the University of Basel, the team vibrated the nanometer-sized tip of an atomic force microscope above the surface of a layered structure of niobium and selenium atoms. They selected this combination due to its unique electronic properties, and in particular the charge-density waves formed at extremely low temperatures. The electrons are no longer evenly distributed as in a metal, but instead form areas where the electron density fluctuates between a high and low range.

Energy losses in the vicinity of charge density waves

The researchers registered very high energy losses in the vicinity of these charge density waves between the surface and the tip of the atomic force microscope, even at relatively large distances of several atomic diameters. “The energy drop was so great, it was as if the tip had suddenly been caught in a viscous fluid,” says Meyer.

The team observed this energy loss only at temperatures below 70° Kelvin (-203° C). Since charge density waves do not occur at higher temperatures, it interpreted this as evidence that frictional forces between the probe tip and charge density waves are the cause of the energy loss.

The theoretical model shows that the high energy loss results from a series of local phase shifts in the charge density waves. This newly discovered phenomenon may be of practical significance in the field of nanotechnology, particularly as the frictional effect can be modulated as a function of distance and voltage.

Original citation
Markus Langer, Marcin Kisiel, Rémy Pawlak, Franco Pellegrini, Giuseppe E. Santoro, Renato Buzio, Andrea Gerbi, Geetha Balakrishnan, Alexis Baratoff, Erio Tosatti and Ernst Meyer
Giant frictional dissipation peaks and charge-density-wave slips at the NbSe2 surface

Nature Materials, published online XXX | doi: 10.1038/NMAT3836

Further information
Prof. Dr. Ernst Meyer, University of Basel, Department of Physics, phone: +41 61 267 37 24, Email: ernst.meyer@unibas.ch

Olivia Poisson | Universität Basel
Further information:
http://www.unibas.ch
http://www.unibas.ch/index.cfm?uuid=DC94C04AD00C6691D7A5CC153F3BD1E9&type=search&show_long=1&o_lang_id=2

More articles from Physics and Astronomy:

nachricht ‘Find the Lady’ in the quantum world
17.10.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht A single photon reveals quantum entanglement of 16 million atoms
16.10.2017 | Université de Genève

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: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

Im Focus: New nanomaterial can extract hydrogen fuel from seawater

Hybrid material converts more sunlight and can weather seawater's harsh conditions

It's possible to produce hydrogen to power fuel cells by extracting the gas from seawater, but the electricity required to do it makes the process costly. UCF...

Im Focus: Small collisions make big impact on Mercury's thin atmosphere

Mercury, our smallest planetary neighbor, has very little to call an atmosphere, but it does have a strange weather pattern: morning micro-meteor showers.

Recent modeling along with previously published results from NASA's MESSENGER spacecraft -- short for Mercury Surface, Space Environment, Geochemistry and...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Taking screening methods to the next level

17.10.2017 | Life Sciences

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

‘Find the Lady’ in the quantum world

17.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>