In 212 B.C.E., Archimedes is said to have used concentrated sunlight to torch the Roman fleet besieging Syracuse. Now Institute researchers have revived this ancient method to produce a high-temperature superconductor with potential industrial applications.
The team of scientists headed by Prof. Shimon Reich "cooked" ceramic material in a solar beam concentrated to 11,000 times the intensity of sunlight reaching the Earth. This clean and fast method, tested at the Institute's Rowland and Sylvia Schaefer Solar Research Complex, marks the first time a superconductor was produced using solar heating.
This ceramic superconductor may one day be used to build a variety of improved mechanical devices, such as frictionless ball bearings that never need oiling, efficient magnetic dampers of mechanical vibrations, and magnetic clutches with no direct contact between the clutch plates. In such equipment, parts that normally glide across or bang against each other would be separated by a cushion of air about 3 mm (one-eight of an inch) deep, and held in place by a magnetic field.
These applications can be envisioned thanks to the unique properties of the superconductor, which carries a strong electric current and makes it possible to suspend magnets in midair.
According to Prof. Reich, fast melting and quenching is essential for making better superconductors, and this is precisely what the solar method provides. In contrast with conventional furnaces, the powerful sunbeam melts the material instantly helping to endow it with desired properties.
Taking part in this project were doctoral students Tatyana Godin and Dario Veretnik and lab assistants Rahamim Rubin and Geula Talmi. The research was supported by the Minerva Foundation, Munich, Germany.
Prof. Reich, a member of the Department of Materials and Interfaces, is the incumbent of the Robert W. Reneker Chair of Industrial Chemistry.