IMPROVED N-LAYER MATERIALS FOR HIGH-T-C SUPERCONDUCTOR NORMAL-METAL/SUPERCONDUCTOR JUNCTIONS AND SUPERCONDUCTING QUANTUM INTERFERENCE DEVICE SENSORS/

In order to solve some of the formidable problems related to producing reliable and reproducible cuprate superconductor/normal-metal/superco nductor (SNS) junctions, new N-layer compounds from the family of R1-x CaxBa2-yLayCu3-zMzO7-delta (R = Y, Gd and Pr; M = Co, Ni and Zn; 0 les s than or equal to x less than or equal to 0.4; 0 less than or equal t o y less than or equal to 0.4; 0 less than or equal to z less than or equal to 0.4) have been synthesized and their properties characterized . Thus, a crystal engineering approach has been adopted in an effort t o generate reliable materials for use in high T-c superconducting devi ces. Careful analyses of the various prepared phases reveal optimum su bstitution levels for selected compositions where the N-layer compound s exhibit structures compatible with common superconductor electrode m aterials. The new compounds have been used for demonstration purposes as the N-layer material for the construction of ramp-edge-geometry SNS junctions and superconducting quantum interference device sensors. (C ) 1998 American Institute of Physics.