Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Electron nanodiffraction technique offers atomic resolution imaging

30.05.2003


A new imaging technique that uses electron diffraction waves to improve both image resolution and sensitivity to small structures has been developed by scientists at the University of Illinois at Urbana-Champaign. The technique works on the same principle as X-ray diffraction, but can record structure from a single nanostructure or macromolecule.



Determining the structure of materials -- such as protein crystals -- is currently performed using X-ray diffraction. However, many small structures used in nanotechnology have not been accessible to crystallography, so their structures remain unknown.

"Nature is full of objects that cannot be easily crystallized, including many proteins and nano-sized objects that lack a periodic structure," said Jian-Min (Jim) Zuo, a professor of materials science and engineering at Illinois and corresponding author of a paper to appear in the May 30 issue of the journal Science. "Our technique has the potential to image nonperiodic nanostructures, including biological macromolecules, at atomic resolution."


To demonstrate the effectiveness of their imaging technique, Zuo and his colleagues recorded and processed the diffraction pattern from a double-wall carbon nanotube.

"Carbon nanotubes are of special interest because the mechanical and electrical properties of a nanotube depend upon its structure," said Zuo, who also is a researcher at the Frederick Seitz Materials Research Laboratory on the Illinois campus. "However, only the outermost shell of a carbon nanotube has been imaged by scanning tunneling microscopy with atomic resolution."

Because carbon possesses few electrons, the scattering from an electron beam is inherently weak and typically results in an image with low contrast and poor resolution, Zuo said. Imaging carbon atoms has been a special challenge.

"While conventional electron microscopes can achieve a resolution approaching1 angstrom for many materials," Zuo said, "the resolution limit for carbon in nanotubes is only 3 angstroms."

To image a double-wall carbon nanotube, the researchers first selected a single nanotube target in a transmission electron microscope. Then they illuminated the nanotube with a narrow beam of electrons about 50 nanometers in diameter. After recording the diffraction pattern, they used an oversampling technique and iterative process to retrieve phase information and construct an image with a resolution of 1 angstrom.

"Since this process does not use a lens to form the image, the resolution is not limited by lens aberration," Zuo said. "Lens aberration is the factor that has been limiting the resolution of the best electron microscopes. It’s like the blur when you look through the bottom of a wine bottle."

The complexity of the nanotube image was surprising, Zuo said. "The double-wall nanotube consists of two concentric nanotubes of different helical angles. Like two screws with different pitch, sometimes the nanotube structures line up and sometimes they don’t. This results in a complicated pattern of both accidental coincidences and mismatches."

The ability to generate images from nanoscale diffraction patterns offers a way to determine the structure of nonperiodic objects, from inorganic nanostructures to biological macromolecules, much like X-ray diffraction does for crystals, Zuo said. "Since diffraction is a standard method for determining structure, our nanoarea electron diffraction technique opens a door to examining the structure of individual and highly irregular molecules and nanostructures like clusters and wires."


###
In addition to Zuo, the team included visiting scientist Ivan Vartanyants and postdoctoral researcher Min Gao at Illinois, and researchers Ruth Zhang and Larry Nagahara at Motorola Labs. The U.S. Department of Energy funded the work.


James E. Kloeppel | UIUC
Further information:
http://www.uiuc.edu/
http://www.mse.uiuc.edu/
http://www.news.uiuc.edu/scitips/03/0529nanodiff.html

More articles from Materials Sciences:

nachricht Nanocrystal 'factory' could revolutionize quantum dot manufacturing
18.03.2019 | North Carolina State University

nachricht Design and validation of world-class multilayered thermal emitter using machine learning
15.03.2019 | National Institute for Materials Science, Japan

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Revealing the secret of the vacuum for the first time

New research group at the University of Jena combines theory and experiment to demonstrate for the first time certain physical processes in a quantum vacuum

For most people, a vacuum is an empty space. Quantum physics, on the other hand, assumes that even in this lowest-energy state, particles and antiparticles...

Im Focus: Sussex scientists one step closer to a clock that could replace GPS and Galileo

Physicists in the EPic Lab at University of Sussex make crucial development in global race to develop a portable atomic clock

Scientists in the Emergent Photonics Lab (EPic Lab) at the University of Sussex have made a breakthrough to a crucial element of an atomic clock - devices...

Im Focus: Sensing shakes

A new way to sense earthquakes could help improve early warning systems

Every year earthquakes worldwide claim hundreds or even thousands of lives. Forewarning allows people to head for safety and a matter of seconds could spell...

Im Focus: A thermo-sensor for magnetic bits

New concept for energy-efficient data processing technology

Scientists of the Department of Physics at the University of Hamburg, Germany, detected the magnetic states of atoms on a surface using only heat. The...

Im Focus: The moiré patterns of three layers change the electronic properties of graphene

Combining an atomically thin graphene and a boron nitride layer at a slightly rotated angle changes their electrical properties. Physicists at the University of Basel have now shown for the first time the combination with a third layer can result in new material properties also in a three-layer sandwich of carbon and boron nitride. This significantly increases the number of potential synthetic materials, report the researchers in the scientific journal Nano Letters.

Last year, researchers in the US caused a big stir when they showed that rotating two stacked graphene layers by a “magical” angle of 1.1 degrees turns...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Researchers measure near-perfect performance in low-cost semiconductors

18.03.2019 | Power and Electrical Engineering

Nanocrystal 'factory' could revolutionize quantum dot manufacturing

18.03.2019 | Materials Sciences

Long-distance quantum information exchange -- success at the nanoscale

18.03.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>