Number 162 (Story #3), January 31, 1994 by Phillip F. Schewe and Ben Stein|
INTERMETALLIC SUPERCONDUCTORS operate in a much colder temperature regime than ceramic superconductors, but may still be important for industrial purposes. A Y-Pd-B-C material developed at AT&T Bell Labs (Robert Cava, 908-582-2180) is superconducting at 23 K, the highest transition temperature yet for a bulk intermetallic compound (Nature, 13 Jan. 1994). This material, at least for now however, is multi-phase, meaning that several phases---each with its own structure---are present in the sample. This complicates the study of superconductivity properties. The same team of scientists has now reported a single-phase material, La-Ni-B-C, which suerconducts at 16.6 K (Nature, 20 Jan). The AT&T scientists believe that these represent the first of what may be a new family of intermetallic superconductors with useful properties. For example, they might facilitate higher magnetic fields than are possible with existing low- temperature superconductors used in making wire, such as Nb-Sn.