A Laboratory at the 91Ö±²¥ Is Officially the Coolest Place in the South
Professor Leonard Spinu's laboratory at the 91Ö±²¥ Advanced Materials Research Institute is officially the coolest place in the South.
UNO-AMRI owns the South's only dry dilution refrigerator, a cooling instrument that can reach temperatures as low as ~8 milliKelvin, which is about -459 Fahrenheit. Its base reaches a temperature as low as ~15mK. The dry dilution refrigerator is the only one in Louisiana and among a handful in the nation.
Other institutions around the globe that own high-technology dilution refrigerators include: the National Institute of Standards and Technology's (NIST's) Center for Nanoscale Science and Technology (CNST), the Kavli Institute for Cosmological Physics at the University of Chicago, the University of California, Berkeley and privately owned organizations such as Oxford Instruments.
Dilution refrigerators are essential to advanced low-temperature nanophysics research and instrumental in other sciences, including astronomy. At 91Ö±²¥-AMRI, researchers are studying iron-based superconductors, said Spinu, who is University research professor of physics and materials sciences at 91Ö±²¥, as well as acting director of AMRI.
A superconductor is a material that can conduct electricity or transport electrons from one atom to another with no resistance. At "critical temperature," or the temperature at which a material becomes superconductive, no heat, sound or any other form of energy is released from the material. Extremely low temperatures are required to explore superconductivity, which is critical to nanoscience or the study of extremely small things.
Using applied research grants from the Louisiana Board of Regents, National Science Foundation and others, Spinu's Spin Dynamics Laboratory studies magnetic materials and devices for information storage and recording, high frequency applications and other technological uses. The Spin Dynamics Laboratory currently partners on its research with academic and industrial organizations in the U.S., Europe and South America.
"Studies of different materials at low temperatures can give better insight into technologically significant properties," said UNO Research Professor of Chemistry John B. Wiley. "Current efforts in the lab involve examining the behavior of different materials at low temperatures — including those that could be useful as new electronic components, for data storage, and in cellular communication devices."
UNO-AMRI's JDry-500-SP1 dilution refrigerator, made by the Janis Research Company, Inc. and bought by UNO in 2009, uses a pulse tube cryocooler, rather than liquid nitrogen or liquid helium, to cool the sample area. Cryogenics is the study of low temperatures.
The dry dilution refrigerator at 91Ö±²¥ "can cool down to properties of various electronic materials, which can change as you cool them down," said Wiley. "For example, a metal will have higher conductivity at lower temperatures."
A Janis spokeswoman said that the company's standard dilution refrigerators can get as cold as 0.009 Kelvin or 9mK. The temperature is out of this world.
"That's called ultra-low temperature," said Janis marketing representative Ann Carroll. "Absolute zero is zero Kelvin and supposedly nothing can get cooler than absolute zero," she said.
"I used to think that [outer] space was absolute zero -- but it's actually warmer than that because of radiation and the Big Bang. Space is actually warmer than zero Kelvin. So our dilution refrigerators get colder than space."
