Study points to an entirely new kind of superconductor

London, May 29 : In a breakthrough study, scientists at the National High Magnetic Field Laboratory at Florida State University, have discovered unique properties in a novel superconducting material, that could lead to a new kind of superconductor.

These surprising magnetic properties in the new materials, which scientists are calling "doped rare earth iron oxyarsenides," were identified by Frank Hunte, a postdoctoral associate at the lab's Applied Superconductivity Center (ASC).

This indicated that these materials may have very powerful applications from improved MRI machines and research magnets to a new generation of superconducting electric motors, generators and power transmission lines. Also, these materials develop superconductivity in quite a new way

"What one would like is a greater selection of superconductors, operating at higher temperatures, being cheaper, possibly being more capable of being made into round wires. Iron and arsenic, both inherently cheap materials, are key constituents of this totally new class of superconductors. We're just fascinated. It's superconductivity in places you never thought of," Nature quoted Larbalestier, director of the ASC, as saying.

While superconductivity is quite promising in its implications, it is still impractical to use it in routine engineering as it requires a very cold environment attainable only with the help of expensive cryogens such as liquid helium or liquid nitrogen.

Based on the findings of previous research and the success of the presence of iron in the material, Larbalestier secured an iron oxyarsenide sample from colleagues at Oak Ridge. He mainly aimed to put it in the magnet lab's 45-tesla Hybrid magnet to see how high a magnetic field the new material could tolerate. (Tesla is a unit of magnetic field strength; the Earth's magnetic field is one twenty thousandth of a tesla.)

Later, it was found that iron oxyarsenide kept superconducting up to 45 tesla, which was much beyond the point at which other superconductors become normal conductors.

Usually, researchers hope for a high tolerance for magnetic field in superconductors. Other desired properties of such materials are the abilities to operate at relatively high temperatures and in the presence of high electrical currents.

These superconducting materials are to make MRI and research magnets, and they are now being tested in a new generation of superconducting electric motors, generators, transformers and power transmission lines. Currently, the most powerful superconducting magnet generates a field of about 26 tesla.

If scientists discover a superconductor that endures a higher current and field, it may pave the way for more powerful magnets, and initiate new researches and power applications.

"So far, based on both theoretical calculations and what we're seeing from the experiments, it seems likely that this is a completely different mechanism for superconductivity," said Hunte.

The study is detailed in the latest issue of the prestigious journal Nature.

ANI