Superconductivity--the state that came in from the cold

The exploration of high transition temperature copper-oxide-based superconductors has proceeded vigorously and internationally during the first year following the initial publication of the work of Bednorz and Müller. Progress in understanding the physics that underlies the phenomena has been slowed by difficulties resulting from the delicate and complex crystal chemistry of the material. Reports of superconducting behavior well above 100 kelvin have not been confirmed to date, although there is some suggestive evidence. A survey of the present state of the science and the possibilities for electronic and electrical power technologies is given.