Tuesday, March 30, 2010

Scientists have discovered the world's smallest superconductor, a sheet of four pairs of molecules less than one nanometer wide


Superconducting materials have an electrical resistance of zero, and so can carry large electrical currents without power dissipation or heat generation. Superconductivity was first discovered in 1911, and until recently, was considered a macroscopic phenomenon. The current finding suggests, however, that it exists at the molecular scale, which opens up a novel route for studying this phenomenon.

In the new study, which was funded by the U.S. Department of Energy, scientist have examined synthesized molecules of a type of organic salt, (BETS)2-GaCl4, placed on a surface of silver. Using scanning tunneling spectroscopy, the scientists observed superconductivity in molecular chains of various lengths. For chains below 50 nanometers in length, superconductivity decreased as the chains became shorter. However, the researchers were still able to observe the phenomenon in chains as small as four pairs of molecules, or 3.5 nanometers in length.

To observe superconductivity at this scale, the scientists needed to cool the molecules to a temperature of 10 Kelvin. Warmer temperatures reduced the activity. In future studies, scientists can test different types of materials that might be able to form nanoscale superconducting wires at higher temperatures.

This is also vital if one wants to fabricate nanoscale electronic circuits using organic molecules
 
With Regards...!

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