Chemical With Superconductivity for High Tempreture Discovered

Description and Advantages

Japanese scientists have discovered a chemical that super conducts electricity at higher temperatures than metals or simple metallic compounds, thereby opening up the possibility of making cheap super conducting wires and devices that operate at accessible temperatures. Jun Akimitsu and his colleagues at the Aoyama Gukuin University in Tokyo have found that magnesium diboride super conducts at 39 kelvin. Akimitsu believes this to be "the highest yet determined for a non-copper-oxide bulk superconductor."

As superconductors offer no resistance to the flow of electric current, they are ideal for power transmission cables and high-speed circuits. The trouble, however, is that they only lose resistance below a critical temperature - below 23 kelvin for metals or simple metallic compounds. In 1986 Swiss scientists had developed a whole new class of ceramic copper oxide superconductors with much higher critical temperatures, sometimes even over 100 kelvin, but these were expensive and difficult to make and use.

"It's terribly exciting," says physicist Lesley Cohen of Imperial College, London. She says one big attraction of magnesium diboride is that it is easy to work with at room temperature. The race is now on to understand how magnesium diboride super conducts, and push it to higher temperatures in conventional materials," says Robert Cava of Princeton University. Researchers at the lowa State University are reported to have already made magnesium diboride super conducting wires.

Date: September 2001