Featured Research

from universities, journals, and other organizations

Friction: Suppression of electronic friction on niobium-films below critical temperature

Date:
January 10, 2011
Source:
Universität Basel
Summary:
Is friction dominated by electrons or by lattice vibrations? A nano-contact experiment shows that on a niobium (Nb) surface friction drops by a factor of three when crossing the superconductivity transition, showing that it has essentially an electronic nature in the metallic state, whereas the phononic contribution dominates in the superconducting state.

Is friction dominated by electrons or by lattice vibrations? A nano-contact experiment shows that on a niobium (Nb) surface friction drops by a factor of three when crossing the superconductivity transition, showing that it has essentially an electronic nature in the metallic state, whereas the phononic contribution dominates in the superconducting state.

Certainly there exist only few physical phenomena attracting people's attention more than friction. 500 years after the first studies of Leonardo da Vinci in the field of sliding friction, scientists still work actively on this topic, employing more sophisticated techniques nowadays capable to probe atomic scale phenomena.

The insight into the atomic world gives the opportunity to study the microscopic origins of friction, which, even today, are poorly known. In particular, is the friction between bodies which are moving with respect to one another, caused by atomic or electronic excitations in the sample? The answer to this question was given by scientists from the group of Ernst Meyer working in the Physics Department of the University of Basel.

The results of the experiment are published in the January 9th issue of Nature Materials.

In the experiment, atomic force sensors were used, oscillating like a tiny pendulum across the niobium (Nb) sample with a few nanometers (1nm=10-9m) amplitude. The frictional forces were measured at different temperatures, across the superconducting transition of Nb. The relative electronic and phononic contributions to the friction could be distinguished, because electrons bound in Cooper pairs cannot contribute to friction. Temperature dependent friction measurements across the critical temperature of Nb films, reveal a reduction of dissipation in the superconductive state compared to the metal state by a factor of 3.

Therefore, the electronically induced friction is the main energy dissipation channel above the transition temperature. This observation is also supported by the dependence of friction force on the probe-sample distance and on the probe-sample voltage.


Story Source:

The above story is based on materials provided by Universität Basel. Note: Materials may be edited for content and length.


Journal Reference:

  1. Marcin Kisiel, Enrico Gnecco, Urs Gysin, Laurent Marot, Simon Rast, Ernst Meyer. Suppression of electronic friction on Nb films in the superconducting state. Nature Materials, 2011; DOI: 10.1038/NMAT2936

Cite This Page:

Universität Basel. "Friction: Suppression of electronic friction on niobium-films below critical temperature." ScienceDaily. ScienceDaily, 10 January 2011. <www.sciencedaily.com/releases/2011/01/110110053216.htm>.
Universität Basel. (2011, January 10). Friction: Suppression of electronic friction on niobium-films below critical temperature. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2011/01/110110053216.htm
Universität Basel. "Friction: Suppression of electronic friction on niobium-films below critical temperature." ScienceDaily. www.sciencedaily.com/releases/2011/01/110110053216.htm (accessed August 21, 2014).

Share This




More Matter & Energy News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Flower Power! Dandelions Make Car Tires?

Flower Power! Dandelions Make Car Tires?

Reuters - Business Video Online (Aug. 20, 2014) — Forget rolling on rubber, could car drivers soon be traveling on tires made from dandelions? Teams of scientists are racing to breed a type of the yellow flower whose taproot has a milky fluid with tire-grade rubber particles in it. As Joanna Partridge reports, global tire makers are investing millions in research into a new tire source. Video provided by Reuters
Powered by NewsLook.com
Awesome New Camouflage Sheet Was Inspired By Octopus Skin

Awesome New Camouflage Sheet Was Inspired By Octopus Skin

Newsy (Aug. 19, 2014) — Scientists have developed a new device that mimics the way octopuses blend in with their surroundings to hide from dangerous predators. Video provided by Newsy
Powered by NewsLook.com
Researcher Testing on-Field Concussion Scanners

Researcher Testing on-Field Concussion Scanners

AP (Aug. 19, 2014) — Four Texas high school football programs are trying out an experimental system designed to diagnose concussions on the field. The technology is in response to growing concern over head trauma in America's most watched sport. (Aug. 19) Video provided by AP
Powered by NewsLook.com
Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

AFP (Aug. 19, 2014) — A solar cell that resembles a flower is offering a new take on green energy in Japan, where one scientist is searching for renewables that look good. Duration: 01:29 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins