Featured Research

from universities, journals, and other organizations

Nanotechnology: Size-specific Cracking Shakes

Date:
August 5, 2008
Source:
DOE/Lawrence Livermore National Laboratory
Summary:
Certain sizes of nanostructures may be more susceptible to failure by fracture than others. As the size of a structure gets to the nanoscale, atomic vibrations (also known as phonons) begin to feel its size and shape in an effect called phonon confinement.

Scanning electron microscope images of a cerium hydride stacked-plate nanostructure. (a) Typical stacked-plate cluster. (b) Close-up view of the edges of the plates in (a). (c) Close-up view of another particle showing a finer fracture scale.
Credit: Image courtesy of DOE/Lawrence Livermore National Laboratory

Certain sizes of nanostructures may be more susceptible to failure by fracture than others.

Related Articles


That is the result of new research by LLNL’s Michael Manley and colleagues from Los Alamos National Laboratory that appears as a Rapid Communication in the journal Physical Review B, August 1.

As the size of a structure gets to the nanoscale, atomic vibrations (also known as phonons) begin to feel its size and shape in an effect called phonon confinement.

While these effects play an important role in thermal transport, electronic processes and thermodynamic stability, not much is known about their role in fracture.

However, in the new research, the scientists found that at a certain thickness, excess entropy of the confined vibrations reduces the fracture energy and results in a size-specific fracture.

Manley and the Los Alamos team found that particles formed during the reaction of cerium with hydrogen (cerium hydride) fractured into stacked plates. The plates exhibited two thickness scales, one at 100 nanometers, and an additional scale at 30-nanometer scale.

“When the fracture results in nanoplates, it leads to a low level of fracture energy at a certain size, resulting in a size-specific fracture,” Manley said. “This has important implications for the design of nanostructures.”

“It also may prove useful in the deliberate creation of large quantities of stable nanostructures,” he said.

Manley said the time scale for phonon excitations typically occurs in picoseconds, while crack growth is a slower process involving the simultaneous displacement of many planes of atoms over a relatively large distance compared to atomic vibrations. “Thus, the phonon confinement should occur instantaneously as the crack propagates,” he said.

Unlike with thermodynamic stability, fracture is a weak-link process, meaning that even a local weakening could be important in dictating the fracture process.

“This could have important consequences, not only for small materials, but also for the way cracks propagate in nanostructured bulk materials,” Manley said.


Story Source:

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


Cite This Page:

DOE/Lawrence Livermore National Laboratory. "Nanotechnology: Size-specific Cracking Shakes." ScienceDaily. ScienceDaily, 5 August 2008. <www.sciencedaily.com/releases/2008/08/080801152147.htm>.
DOE/Lawrence Livermore National Laboratory. (2008, August 5). Nanotechnology: Size-specific Cracking Shakes. ScienceDaily. Retrieved January 30, 2015 from www.sciencedaily.com/releases/2008/08/080801152147.htm
DOE/Lawrence Livermore National Laboratory. "Nanotechnology: Size-specific Cracking Shakes." ScienceDaily. www.sciencedaily.com/releases/2008/08/080801152147.htm (accessed January 30, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Friday, January 30, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Tesla 'Insane Mode' Gives Unsuspecting Passengers the Ride of Their Life

Tesla 'Insane Mode' Gives Unsuspecting Passengers the Ride of Their Life

RightThisMinute (Jan. 29, 2015) — If your car has an "Insane Mode" then you know it&apos;s fast. Well, these unsuspecting passengers were in for one insane ride when they hit the button. Tesla cars are awesome. Video provided by RightThisMinute
Powered by NewsLook.com
Now Bill Gates Is 'Concerned' About Artificial Intelligence

Now Bill Gates Is 'Concerned' About Artificial Intelligence

Newsy (Jan. 29, 2015) — Bill Gates joins the list of tech moguls scared of super-intelligent machines. He says more people should be concerned, but why? Video provided by Newsy
Powered by NewsLook.com
Senate Passes Bill for Keystone XL Pipeline

Senate Passes Bill for Keystone XL Pipeline

AP (Jan. 29, 2015) — The Republican-controlled Senate has passed a bipartisan bill approving construction of the Keystone XL oil pipeline. (Jan. 29) Video provided by AP
Powered by NewsLook.com
Two Stunt Pilots Perform Incredibly Close Flyby

Two Stunt Pilots Perform Incredibly Close Flyby

Rumble (Jan. 29, 2015) — Two pilots from &apos;Escuadrilla Argentina de Acrobacia Aιrea&apos; perform an incredibly low altitude flyby stunt during a recent show exhibition in Argentina. Check it out! Video provided by Rumble
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