7 June 2013

MagLab scientists publish Science paper on super-atom arrays


TALLAHASSEE, Fla. — Two Magnet Lab scientists, in collaboration with other researchers, have assembled super-atomic structures and published their findings in the prestigious periodical Science.

Theo Siegrist. Theo Siegrist. The paper, “Nanoscale Atoms in Solid-State Chemistry,” reflects the findings of a team of researchers, including the MagLab’s Theo Siegrist, a Florida State University professor at the Florida A&M University-FSU College of Engineering, and Tiglet Besara, a postdoctoral research associate in condensed matter. Researchers at Columbia University, Rutgers State University, the State University of New York and Barnard College also collaborated on the paper.

The paper reflects a relatively new area in materials research that scientists are eager to explore.

“Instead of just assembling atoms, we are preassembling the atoms into a cluster, and then we take those blocks and assemble them,” said Siegrist, who is also a condensed matter researcher at the MagLab. “We are building super-atoms, one of which is C60, or a buckyball.”

This is a super-atom assembly containing two distinct super atoms. This is a super-atom assembly containing two distinct super atoms. One is a buckyball, or C60. The other is a cluster of elements: Co6Se8P6C36H90 (cobalt, selenium, phosphorus, carbon and hydrogen). Buckyballs, or buckminsterfullerenes, are carbon molecules that form spheres that resemble soccer balls. Their discovery led to the exploration of a new field of chemistry; FSU Professor Sir Harold Kroto was part of a team that discovered buckyballs and won the 1996 Nobel Prize in Chemistry for it.

Now Siegrist and others are exploring different ways to combine buckyballs and other new solid-state compounds. To picture what these scientists are doing, imagine you want to build something with Lego toys, those classic, colorful, interlocking plastic bricks. But rather than starting with individual Legos, you could begin with larger, preassembled Lego pieces. These researchers are fabricating those larger, preassembled pieces.

"It’s a new concept,” Siegrist says. “We are building a higher-order material.”

Now he and other researchers want to learn more about the properties of these super-atomic building blocks.

“We know that these super-atoms exchange, or share, electrons. So we get conductivity, we get magnetic behavior, and we even see ferromagnetic behavior” or materials transforming into magnets, Siegrist said. “One of the things that could be really interesting down the road would be learning more about the magnetic properties of these super-atomic arrays.”

Tiglet Besara. Tiglet Besara. In addition to Siegrist and Besara, the researchers who collaborated on the Science paper are: Xavier Roy, Chul-Ho Lee, Christine Schenck, Louis Brus, Philip Kim, Michael Steigerwald and Colin Nuckolls, all of Columbia University; Andrew Crowther of Barnard College in New York; Roger Lalancette of Rutgers State University in New Jersey; and Peter Stephens of SUNY Stony Brook and the National Synchrotron Light Source at Brookhaven National Lab in New York.

The National High Magnetic Field Laboratory is the world’s largest and highest-powered magnet facility. Located at Florida State University, the University of Florida and Los Alamos National Laboratory, the interdisciplinary National MagLab hosts scientists from around the world to perform basic research in high magnetic fields, advancing our understanding of materials, energy and life. The lab is funded by the National Science Foundation (DMR-1157490) and the state of Florida. For more information, visit us online at nationalmaglab.org or follow us on Facebook, Twitter, Instagram and Pinterest at NationalMagLab.