HIGH-T-C SUPER-CONDUCTING QUANTUM INTERFERENCE DEVICES WITH SLOTS OR HOLES - LOW 1 F NOISE IN AMBIENT MAGNETIC-FIELDS/

High-transition temperature de superconducting quantum interference de vices (SQUIDs) have been fabricated with arrays of slots or holes patt erned in the 186x204 mu m(2) washers. In two designs, with seven slots or 248 holes, the linewidth of the remaining YBa2Cu3O7-x, film was 4 mu m. These devices exhibited virtually no increase in their low-frequ ency noise when they were cooled in static magnetic fields up to a cer tain threshold, above 100 mu T in the best case. Furthermore, the mutu al inductance between these devices and a seven-turn, spiral coil was at least 85% of that for a solid SQUID with the same outer dimensions. (C) 1997 American Institute of Physics.