Learning to see atoms

April 5th, 2011
World-leading atom probe tomography expert discusses state of the science, solving materials challenges

Well versed in the history of atom probe imaging, Dr. Michael K. Miller of Oak Ridge National Laboratory spoke on the promises and challenges of atom probe tomography, which provides three-dimensional images of atoms in a sample. The talk was given to a packed room as part of the Frontiers in Chemical Imaging Seminar Series. This series, hosted by Pacific Northwest National Laboratory, features academic, government, and industrial leaders discussing novel advances in imaging.

"Miller literally wrote the book on atom probe tomography," said Dr. Lou Terminello, who leads the Chemical Imaging Initiative at Pacific Northwest National Laboratory.

Promises Made. In designing catalysts to transform intermittent renewable energy into use-any-time fuels, scientists examine new materials, made by adding small amounts of different elements to existing materials. Adding an element, especially where a material's crystalline grains intersect - a boundary -- can change a material's properties significantly. Using atom probe tomography, researchers can obtain sharp, 3D images of the atoms with their chemical identity.

"We can obtain incredibly detailed and beautiful images of atoms in a sample," said Miller.

With these images, scientists can determine a lot about the atoms on the surface, including the quantity and location of different atoms. This information could help analyze the characteristics of complex oxide based insulating materials and materials used in nuclear reactors.

Challenges Before Us. However, obtaining meaningful or scientifically significant images requires overcoming two challenges. The first is setting up the experiment itself. The scientist must create a very sharp "needle" of a sample. Depending on the properties of the material, creating the sample can be especially difficult. However, shaping the sample perfectly makes all the difference. Further, scientists must establish appropriate experimental conditions to obtain accurate data.

"It is not a simple system, where you just plug something in and use it," said Dr. Satya Kuchibhatla, a materials scientist on the Chemical Imaging Initiative. Kuchibhatla also leads research on the new atom probe system in EMSL.

The second challenge is interpreting the data, which is generated at a rate of up to 16 gigabytes per experiment. Researchers need to be able to quickly and accurately distinguish between artifacts in the images and the real features.

"Miller's talk really inspires me to continue my work in atom probe tomography," said Kuchibhatla, who is giving an invited talk at Surface Analysis 2011 in Albany, New York.

Provided by Pacific Northwest National Laboratory

This Phys.org Science News Wire page contains a press release issued by an organization mentioned above and is provided to you “as is” with little or no review from Phys.Org staff.

More news stories

Physicists design zero-friction quantum engine

(Phys.org) —In real physical processes, some energy is always lost any time work is produced. The lost energy almost always occurs due to friction, especially in processes that involve mechanical motion. ...

King Richard III died painfully on battlefield

England's King Richard III might well have lost his kingdom for a horse. The reviled king suffered nearly a dozen injuries on the battlefield, but the fatal blows were probably only sustained after he had to abandon his horse, ...

Healthy humans make nice homes for viruses

The same viruses that make us sick can take up residence in and on the human body without provoking a sneeze, cough or other troublesome symptom, according to new research at Washington University School ...