Featured Research

from universities, journals, and other organizations

Strange new nano-region can form in quasicrystals

Date:
February 16, 2012
Source:
DOE/Ames Laboratory
Summary:
Researchers have discovered a new type of structural anomaly, or defect, that can appear in quasicrystals, a unique material with some crystal-like properties but a more complex structure. The new defect type occurs under certain circumstances to help balance competing energetic issues. The defect's formation at those times enables higher-energy transition-metal-rich surfaces to be exposed rather than the expected lower-energy aluminum-rich surfaces.

Researchers have discovered a new type of structural anomaly, or defect, that can appear in quasicrystals.
Credit: Image courtesy of DOE/Ames Laboratory

A team of international researchers has discovered a new type of structural anomaly, or defect, that can appear in quasicrystals, a unique material with some crystal-like properties but a more complex structure.

Pat Thiel, senior chemist at the U.S. Department of Energy's Ames Laboratory, led the international team, which includes scientists from the Institut Jean Lamour at Nancy-Université in France.

In crystals, a "defect" refers to any departure from perfect structural symmetry. While the term suggests an undesirable quality, not all defects are bad; many control or influence key material properties, such as chemical purity, mechanical strength, conductivity, color, corrosivity or surface properties. Rubies, for instance, are red due to a defect that turns an otherwise non-descript crystal into a valuable gem.

Quasicrystals were already known to have a type of defect called a phason flip, which can form at the surface. The new defect type was discovered after researchers observed mysterious nano-sized areas on quasicrystal surfaces. Unlike the phason flip, however, the new defect type extends beyond the surface region and into the bulk of the quasicrystal.

"Quasicrystals are such fascinating materials -- they seem to always exhibit features that are unexpected, starting with their very existence," said Thiel, who is also Iowa State University's John D. Corbett Distinguished Professor of Chemistry.

It wasn't until 1982, in fact, when Dan Shechtman observed the seemingly impossible -- a well-defined but non-repeating arrangement of atoms under his electron microscope -- that quasicrystals were found to exist. It took even longer for the scientific community to accept their existence. Shechtman, a materials scientist with Ames Lab, Iowa State University and Technion-Israel Institute of Technology, won the 2011 Nobel Prize in Chemistry for his discovery.

The recent discovery of the new defect type shows quasicrystals are still yielding surprises. While the nanodomain defect isn't always present -- it only occurs under certain circumstances to help balance competing energetic issues -- its formation at those times enables higher-energy transition-metal-rich surfaces to be exposed rather than the expected lower-energy aluminum-rich surfaces.

Because nanostructures show promise for use in a range of applications, from medical to electronics, understanding the relationship between surface and bulk defects in materials may yield greater insights into why nanostructures are often unusually strong.

"It's already known that in nanowires, their strength is related to the fact that the surface can 'erase' the bulk defects," Thiel said. "But then eventually under extreme conditions even a nanowire can fail, and the surface seems to play a role in that event as well. So the relationship between surface and bulk defects really is very important."


Story Source:

The above story is based on materials provided by DOE/Ames Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. T. Duguet, B. Ünal, J. Ledieu, J.-M. Dubois, V. Fournée, P. Thiel. Nanodomains due to Phason Defects at a Quasicrystal Surface. Physical Review Letters, 2011; 106 (7) DOI: 10.1103/PhysRevLett.106.076101

Cite This Page:

DOE/Ames Laboratory. "Strange new nano-region can form in quasicrystals." ScienceDaily. ScienceDaily, 16 February 2012. <www.sciencedaily.com/releases/2012/02/120216165707.htm>.
DOE/Ames Laboratory. (2012, February 16). Strange new nano-region can form in quasicrystals. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2012/02/120216165707.htm
DOE/Ames Laboratory. "Strange new nano-region can form in quasicrystals." ScienceDaily. www.sciencedaily.com/releases/2012/02/120216165707.htm (accessed October 1, 2014).

Share This



More Matter & Energy News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Argentina's Tax Evaders Detected, Hunted Down by Drones

Argentina's Tax Evaders Detected, Hunted Down by Drones

AFP (Sep. 30, 2014) — Argentina doesn't only have Lionel Messi the footballer, it has now also acquired "Mesi" the drone system which monitors undeclared mansions, swimming pools and soy fields to curb tax evasion in the country. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Do Video Games Trump Brain Training For Cognitive Boosts?

Do Video Games Trump Brain Training For Cognitive Boosts?

Newsy (Sep. 29, 2014) — More and more studies are showing positive benefits to playing video games, but the jury is still out on brain training programs. Video provided by Newsy
Powered by NewsLook.com
CERN Celebrates 60 Years of Science

CERN Celebrates 60 Years of Science

Reuters - Business Video Online (Sep. 29, 2014) — CERN, the European Organisation for Nuclear Research, celebrates 60 years of bringing nations together through science. As Joanna Partridge reports from inside the famous science centre it's also planning to turn the Large Hadron Collider particle accelerator back on after an upgrade. Video provided by Reuters
Powered by NewsLook.com
This 'Invisibility Cloak' Is Simpler Than Most

This 'Invisibility Cloak' Is Simpler Than Most

Newsy (Sep. 28, 2014) — Researchers from the University of Rochester have created a type of invisibility cloak with simple focal lenses. Video provided by Newsy
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:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

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