Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > New imaging technique reveals the atomic structure of nanocrystals

Photo by L. Brian Stauffer
Jian-Min (Jim) Zuo, a professor of materials science and engineering, has developed a new imaging technique that can reveal the atomic structure of a single nanocrystal with a resolution of less than one angstrom (less than one hundred-millionth of a centimeter).
Photo by L. Brian Stauffer
Jian-Min (Jim) Zuo, a professor of materials science and engineering, has developed a new imaging technique that can reveal the atomic structure of a single nanocrystal with a resolution of less than one angstrom (less than one hundred-millionth of a centimeter).

Abstract:
A new imaging technique developed by researchers at the University of Illinois overcomes the limit of diffraction and can reveal the atomic structure of a single nanocrystal with a resolution of less than one angstrom (less than one hundredth-millionth of a centimeter).

New imaging technique reveals the atomic structure of nanocrystals

Champaign, IL | Posted on February 18th, 2009

Optical and electronic properties of small assemblages of atoms called quantum dots depend upon their electronic structure - not just what's on the surface, but also what's inside. While scientists can calculate the electronic structure, they need to know where the atoms are positioned in order to do so accurately.

Getting this information, however, has proved to be a challenge for nanocrystals like quantum dots. Mapping out the positions of atoms requires clues provided by the diffraction pattern. But quantum dots are so small, the clues provided by diffraction alone are not enough.

By combining two sources of information - images and diffraction patterns taken with the same electron microscope - researchers at the U. of I. can achieve sub-angstrom resolution of structures that were not possible before.

"We show that for cadmium-sulfide nanocrystals, the improved image resolution allows a determination of their atomic structures," said Jian-Min (Jim) Zuo, a professor of materials science and engineering at the U. of I., and corresponding author of a paper that describes the high-resolution imaging system in the February issue of Nature Physics.

Images from electron microscopy can resolve individual atoms in a nanocrystal, but the atoms soon suffer radiation damage, which limits the length of observations. Patterns from X-ray diffraction can be used to determine the structure of large crystals, but not for nanocrystals, which are too small and don't diffract well.

To achieve sub-angstrom resolution, Zuo and colleagues developed a reiterative algorithm that processes and combines shape information from the low-resolution image and structure information from the high-resolution diffraction pattern. Both the image and the diffraction pattern are taken with the same transmission-electron microscope.

"The low-resolution image provides the starting point by supplying missing information in the central beam and supplying essential marks for aligning the diffraction pattern," said Zuo, who also is a researcher at the university's Frederick Seitz Materials Research Laboratory. "Our phase-retrieval algorithm then reconstructs the image."

To demonstrate the technique, the researchers took a new look at cadmium-sulfide quantum dots.

"We chose cadmium-sulfide quantum dots because of their size-dependent optical and electronic properties, and the importance of atomic structure on these properties," Zuo said. "Cadmium-sulfide quantum dots have potential applications in solar energy conversion and in medical imaging."

Using the reiterative algorithm, the smallest separation between the cadmium and sulfide atomic columns was measured at 0.84 angstroms, the researchers report.

"Since low-resolution images can be obtained from different sources, our technique is general and can be applied to non-periodic structures, such as interfaces and local defects," Zuo said. "Our technique also provides a basis for imaging the three-dimensional structure of single nanoparticles."

With Zuo, co-authors of the paper are former doctoral student and lead author Weijie Huang (now at Dow Chemical Co.), U. of I. professor of materials science and engineering Moonsub Shim, former postdoctoral research associate Bin Jiang (now at FEI Co.), and former doctoral student Kwan-Wook Kwon (now at LAM Research).

The U.S. Department of Energy, the American Chemical Society and the National Science Foundation funded the work

####

For more information, please click here

Contacts:
James E. Kloeppel
Physical Sciences Editor
217-244-1073


Jian-Min Zuo
217-244-6504

Copyright © University of Illinois at Urbana-Champaign

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Building a smart cardiac patch: 'Bionic' cardiac patch could one day monitor and respond to cardiac problems June 28th, 2016

New, better way to build circuits for world's first useful quantum computers June 28th, 2016

Yale researchersí technology turns wasted heat into power June 27th, 2016

FEI Launches Helios G4 DualBeam Series for Materials Science: The Helios G4 DualBeam Series features new capabilities to enable scientists and engineers to answer the most demanding and challenging scientific questions June 27th, 2016

Superheroes are real: Ultrasensitive nonlinear metamaterials for data transfer June 25th, 2016

Imaging

FEI Launches Helios G4 DualBeam Series for Materials Science: The Helios G4 DualBeam Series features new capabilities to enable scientists and engineers to answer the most demanding and challenging scientific questions June 27th, 2016

Ultrathin, flat lens resolves chirality and color: Multifunctional lens could replace bulky, expensive machines June 25th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Nanoscientists develop the 'ultimate discovery tool': Rapid discovery power is similar to what gene chips offer biology June 25th, 2016

Ultrathin, flat lens resolves chirality and color: Multifunctional lens could replace bulky, expensive machines June 25th, 2016

Particle zoo in a quantum computer: First experimental quantum simulation of particle physics phenomena June 23rd, 2016

Titan shines light on high-temperature superconductor pathway: Simulation demonstrates how superconductivity arises in cuprates' pseudogap phase June 22nd, 2016

Discoveries

Building a smart cardiac patch: 'Bionic' cardiac patch could one day monitor and respond to cardiac problems June 28th, 2016

New, better way to build circuits for world's first useful quantum computers June 28th, 2016

Yale researchersí technology turns wasted heat into power June 27th, 2016

Superheroes are real: Ultrasensitive nonlinear metamaterials for data transfer June 25th, 2016

Announcements

Building a smart cardiac patch: 'Bionic' cardiac patch could one day monitor and respond to cardiac problems June 28th, 2016

New, better way to build circuits for world's first useful quantum computers June 28th, 2016

Yale researchersí technology turns wasted heat into power June 27th, 2016

FEI Launches Helios G4 DualBeam Series for Materials Science: The Helios G4 DualBeam Series features new capabilities to enable scientists and engineers to answer the most demanding and challenging scientific questions June 27th, 2016

Tools

FEI Launches Helios G4 DualBeam Series for Materials Science: The Helios G4 DualBeam Series features new capabilities to enable scientists and engineers to answer the most demanding and challenging scientific questions June 27th, 2016

Nanoscientists develop the 'ultimate discovery tool': Rapid discovery power is similar to what gene chips offer biology June 25th, 2016

Ultrathin, flat lens resolves chirality and color: Multifunctional lens could replace bulky, expensive machines June 25th, 2016

Researchers discover new chemical sensing technique: Technique allows sharper detail -- and more information -- with near infrared light June 24th, 2016

Quantum Dots/Rods

A new form of hybrid photodetectors with quantum dots and graphene June 19th, 2016

Supercrystals with new architecture can enhance drug synthesis May 24th, 2016

ORNL demonstrates large-scale technique to produce quantum dots May 21st, 2016

First single-enzyme method to produce quantum dots revealed: Biological manufacturing process, pioneered by three Lehigh University engineers, produces equivalent quantum dots to those made chemically--but in a much greener, cheaper way May 9th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic