Featured Research

from universities, journals, and other organizations

Physicists Get First Glimpse Of Nanoscale Molecular Behavior

Date:
November 9, 2000
Source:
North Carolina State University
Summary:
A team of North Carolina State University physicists has discovered a new method for measuring the molecular properties of materials, which could assist in the development of a wide variety of cutting-edge nanostructure technologies. The technique -- called Gradient-Field-Raman (GFR) spectroscopy -- measures the behavior of molecules, at a scale of one-billionth of a meter, by reflecting light off the material being studied.

A team of North Carolina State University physicists has discovered a new method for measuring the molecular properties of materials, which could assist in the development of a wide variety of cutting-edge nanostructure technologies.The technique -- called Gradient-Field-Raman (GFR) spectroscopy -- measures the behavior of molecules, at a scale of one-billionth of a meter, by reflecting light off the material being studied.

Dr. Hans D. Hallen, assistant professor of physics at NC State, has found molecules reacting differently to the light than would be expected using the previously most advanced spectroscopy technique for studying the vibrations of molecules or solids. The new GFR spectroscopy takes advantage of these differences.

Hallen, along with former students Eric Ayars and Catherine Jahncke, is publishing those results in the Nov. 6 edition of the physics journal Physical Review Letters.

"Using Gradient-Field-Raman spectroscopy, we can look at nanostructures of all sorts: semiconductors, biological materials and nanofabricated structures," Hallen said. "If you have something small, nanometers in size, and want to know how it fits together, this is the way to do it."

Scientists and engineers across the nation are currently engaged in a major nanotechnology research push. Their goal is to develop the ability to build new materials at the molecular level. Potential new materials include structures stronger than steel but much lighter, minuscule transistors and memory chips, DNA-based structures, quantum wires and laser emitters.

Science policy experts say nanotechnology advances could result in a science and technology revolution. But first, they say, we have to understand the principles of structures at such tiny scales.

The work of Hallen and his colleagues is an important step in that direction.

GFR spectroscopy is similar in principle to Raman spectroscopy, but with resolution measured in nanometers (or one-billionth of a meter) rather than in millimeters. Raman spectroscopy was developed in the 1920s and refined in the 1970s to study materials at a microscopic scale (at one-millionth of a meter). With both Raman and GFR spectroscopy, light directed at a sample is reflected from the sample at a different frequency than the light's initial frequency. The frequency difference, caused by the coupling of the light photons with bonds in the molecule or solid, indicates the vibration and rotation of the molecules being studied.

In normal Raman spectroscopy, the coupling between the light and the molecule is brought about by a change in polarizability as the molecule vibrates along a bond. But when Hallen and his colleagues used a new instrument -- called a near-field scanning optical microscope -- to get a closer look, they discovered vibration patterns that couldn't be explained using the rules associated with normal Raman spectroscopy.

They then discovered that the coupling between the light and molecule in GFR spectroscopy is moderated by a strong electric field gradient that shifts the potential energy of the atoms as they move during the vibration.

"This helps you pick apart the various vibrations at the surface of a sample a little bit better than you could before," Hallen said. "You can get a good, almost three-dimensional, picture of the vibration modes."

More information about Hallen's research is on the Web at http://www.physics.ncsu.edu/optics.


Story Source:

The above story is based on materials provided by North Carolina State University. Note: Materials may be edited for content and length.


Cite This Page:

North Carolina State University. "Physicists Get First Glimpse Of Nanoscale Molecular Behavior." ScienceDaily. ScienceDaily, 9 November 2000. <www.sciencedaily.com/releases/2000/11/001107070342.htm>.
North Carolina State University. (2000, November 9). Physicists Get First Glimpse Of Nanoscale Molecular Behavior. ScienceDaily. Retrieved October 2, 2014 from www.sciencedaily.com/releases/2000/11/001107070342.htm
North Carolina State University. "Physicists Get First Glimpse Of Nanoscale Molecular Behavior." ScienceDaily. www.sciencedaily.com/releases/2000/11/001107070342.htm (accessed October 2, 2014).

Share This



More Matter & Energy News

Thursday, October 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Japan Looks To Faster Future As Bullet Train Turns 50

Japan Looks To Faster Future As Bullet Train Turns 50

Newsy (Oct. 1, 2014) Japan's bullet train turns 50 Wednesday. Here's a look at how it's changed over half a century — and the changes it's inspired globally. Video provided by Newsy
Powered by NewsLook.com
US Police Put Body Cameras to the Test

US Police Put Body Cameras to the Test

AFP (Oct. 1, 2014) Police body cameras are gradually being rolled out across the US, with interest surging after the fatal police shooting in August of an unarmed black teenager. Duration: 02:18 Video provided by AFP
Powered by NewsLook.com
Raw: Japan Celebrates 'bullet Train' Anniversary

Raw: Japan Celebrates 'bullet Train' Anniversary

AP (Oct. 1, 2014) A ceremony marking 50 years since Japan launched its Shinkansen bullet train was held on Wednesday in Tokyo. The latest model can travel from Tokyo to Osaka, a distance of 319 miles, in two hours and 25 minutes. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Robotic Hair Restoration

Robotic Hair Restoration

Ivanhoe (Oct. 1, 2014) A new robotic procedure is changing the way we transplant hair. The ARTAS robot leaves no linear scarring and provides more natural results. Video provided by Ivanhoe
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