7 April 2011

From hospitals to Hollywood: Where will superconductors show up next?


It's right there with you inside an MRI machine, and it made a cameo appearance in the blockbuster film "Avatar." A century after its discovery, superconductivity is showing up in more and more places.

Now you can learn more about this phenomenon and the amazing materials that make it possible at the next Magnet Mystery Hour on Tuesday, April 19, at the Magnet Lab in Innovation Park. The presentation starts at 7 p.m. and lasts about an hour. If you'd like a short tour of the lab, arrive at 6:30 p.m. It's all free."MRIs are really the biggest application of superconductors so far, but we think there could be more in the near future," said Eric Hellstrom, who will give the presentation. Hellstrom is a researcher with the lab's Applied Superconductivity Center and a professor of mechanical engineering at the FAMU-FSU College of Engineering.

The first superconducting material — mercury — was discovered April 8, 1911, in a lab at Leiden University in The Netherlands. Dutch physicist Heike Kamerlingh Onnes (who had a lifelong fascination with how matter changes at super-cold temperatures) was stunned to discover that at 4 kelvins, or minus 452 degrees Fahrenheit, mercury conducted electricity with no power loss.

Since then, many superconductors have been discovered from materials that include metals, alloys and even ceramics. In order for electrical current to flow through them without resistance, however, all of the superconductors discovered so far must be kept extremely cold. And it's these expensive, complex and cumbersome cooling systems that hold superconductors back from far greater usage.

At the Magnet Lab's Applied Superconductivity Center, Hellstrom and his coworkers are investigating a new superconductor that contains arsenic — yes, the same poisonous material that often plays a deadly role in murder mysteries (including the classic, "Arsenic and Old Lace"). Arsenic, Hellstrom said, can be found in more than a few unexpected places these days.That's why many researchers continue to search for a room-temperature superconductor — the elusive Holy Grail of superconductors. In "Avatar," the fictional, room-temperature superconductor was dubbed "unobtainium," and humans came to the alien planet at great expense to mine for it.

"When you make a call on your cell phone," he said, "you are holding arsenic in your hand. It is in the gallium-arsenide electrical circuits that help power the phone."

In the 100 years since superconductivity was discovered, scientists have created several combinations of materials that superconduct at "warmer" temperatures. Today, the warmest — Hellstrom likes to use the word "hottest" — superconductor works at a mere 160 K, or a still mighty frosty minus 171 degrees F.

Is the elusive "unobtainium" just around the bend? Or is it nothing more than Hollywood fiction?

Come hear what Hellstrom has to say at the April 19 Magnet Mystery Hour.

Magnet Mystery Hour is an ongoing series of talks that present the lab, its instruments and its research in a way that's accessible to the curious-minded, even if they haven't had a science class since high school (or are currently in high school!). The talks are presented by the scientists themselves — many of them leaders in their fields — in a conversational format appropriate for older students and adults.