Superconductor is Virtually Immune to Magnetism

Frank Hunte, a postdoctoral associate at the National High Magnetic Field Laboratory’s Applied Superconductivity Center has discovered surprising magnetic properties in new superconductors that suggest they may have very powerful applications allowing for dramatically faster computers free of the burden of resistance-produced waste heat as well as improved MRI devices and a new generation of superconducting electric motors more efficient then any current motor.




 

 Frank Hunte (Credit: National High Magnetic Field Laboratory)
Frank Hunte
(Credit: National High
Magnetic Field Laboratory)

Currently three critical weaknesses of superconductors stand in the way of many cutting edge advances. First and foremost is their temperature dependence, requiring temperatures well beneath the means of even standard liquid nitrogen cooling. The critical temperature is somewhat pressure dependent, so extremely high pressure superconductors can superconduct at higher temperatures.

Two lesser known, but not lesser important, limitations of superconductors include a sensitivity to high currents as well as to magnetism. At high currents, superconductors can cease functioning properly, and magnetic fields are particularly deadly to superconductors, easily reverting them back to normal conductors.

Recently there was a new breakthrough discovered by Japanese researchers that had been looking into iron superconductors, and found a unique class of superconductors which seem to be amazingly almost completely immune to magnetism. This breakthrough could remove one of the largest obstacles to commercializing superconducting.

 scanning electron/focused ion beam microscope, one of two at the center, is used to develop highly energy efficient superconducting wires and tapes (credit: National High Magnetic Field Laboratory)
A scanning electron/focused ion beam
microscope used to develop highly
energy efficient superconducting wires
and tapes (Credit: National High
Magnetic Field Laboratory)

The scientists used an atypical combination of metals to the superconductor material; they added a bit of arsenic to the mix to create iron oxyarsenide – which, as the name implies, also featured oxygen. The new material also contains the rare earth metal lanthanum which can superconduct at 26 K (-413 degrees Fahrenheit). As iron typically creates a magnetic field when conducting, researchers were surprised to find a fully working superconductor which included iron. Somehow, the superconductor was surviving the magnetic field, an unexpected first.

Many possible applications await the improvement of this new technology, including ultra-efficient superconducting motors and power transmission lines. They could also be used in new superconducting magnets, which would open up a new world of research opportunities in diverse fields of science. As Hunte states, “The field is completely open. No one knows where this is going to go. If it’s found that these materials can support high current densities, then they could be tremendously useful.”

TFOT recently covered the illogical secret of superconductors which described a recent research study which uncovered part of the mechanism that transforms matter into a high-temperature superconductor; also covered was the demonstration of the first quantum computer, which uses superconductors for its operation, developed by the Canadian Company D-Wave.

More on the new superconductors can be found on the National High Magnetic Field Laboratory’s Applied Superconductivity Center website.