Number 207 (Story #1), December 15, 1994 by Phillip F. Schewe and Ben Stein COPPERLESS PEROVSKITE SUPERCONDUCTORS have been devised by a collaboration of physicists at IBM Zurich and Hiroshima University. Perovskite, a class of ceramic crystal (e.g., MgSiO3) in which three chemical elements combine in the ratio 1:1:3 to form a layered cubic structure, is prominent in the Earth's mantle. It became even more famous when over the past eight years a series of superconducting perovskites were discovered. The superconductivity in these compounds appears to reside in planar networks of copper and oxygen and scientists have wondered whether copper was crucial. Copper may well be special but now ruthenium-oxygen planes seem to carry superconductivity too. The Hiroshima-IBM material, a Sr-Ru-O compound, only becomes superconducting at 0.93 K, but the researchers believe that by studying the new "ruthenate" materials we will learn more about the higher-temperature cuprate materials. (Y. Maeno et al., Nature, 8 December 1994.)