Number 289 (Story #3), October 3, 1996 by Phillip F. Schewe and Ben Stein NANOROD-SUPERCONDUCTOR COMPOSITES might be able to carry high currents. One of the biggest obstacles to the greater application of high-temperature superconductors (HTSC) is that in the presence of large magnetic fields the bundles of magnetic flux lines within the superconductor begin to move about, causing energy dissipation and sometimes even the loss of the superconducting state. In an effort to pin the flux bundles in place, Harvard scientists Peidong Yang and Charles Lieber incorporate tiny defects in the form of magnesium oxide nanorods in their HTSC samples. The use of the nanorods increases the critical current, the maximum allowable current, by factors of up to 10 or more. The improvement in current density is highest for large fields and higher temperatures. Defects have been used before to control flux motion, but in previous experiments the defects were created by the use of heavy-ion or proton irradiation, a process which would be cumbersome if applied to commercial processing. (Science, 27 September 1996.)