TRANSPORT PROPERTIES OF JOSEPHSON JUNCTIONS AND SQUIDS EMPLOYING DIFFERENT TYPES OF YBCO GRAIN BOUNDARIES OBTAINED THROUGH THE BIEPITAXIAL TECHNIQUE

Concepts and experimental procedures to obtain different types of YBa 2 Cu 3 O 7 grain boundaries Josephson junction through the biepitaxial technique have been developed. Various seed layers (MgO, CeO 2 and SrTiO 3) and substrates (MgO, SrTiO 3) have been used providing, for the biepitaxial technique, additional flexibility in circuit design. A detailed investigation on transport properties evidenced good performances for both junctions and superconducting quantum interference devices. Experimental evidence is given of a conventional magnetic field behavior in 45° tilt Artificial Grain Boundary (AGB) for which no π-loops are predicted along the interface.