FABRICATION OF EU1BA2CU3OY THIN-FILMS AND TUNNEL-JUNCTIONS BY MAGNETRON SPUTTERING

Epitaxial Eu1Ba2Cu3O(y) (EBCO) thin films have been grown in-situ on SrTiO3, and MgO (001) by dc magnetron sputtering from a stoichiometric sintered target. The controllable production of films with a particular orientation is found to be possible through sputtering process. A high degree of crystalline quality for purely a-axis oriented films on SrTiO3 (001) is revealed by 4-axis gonio X-ray diffraction and RBS study (chi-min of 10% for 7 MeV He-4(2+) ion channeling). Zero resistivity transition temperature obtained for completely a-axis oriented film is 88 K, and 93 K for c-axis oriented film. Tunnel junctions are fabricated using in-situ deposited EBCO/Au/MgO/Nb structures and a photolithographic technique. The in-situ grown, smooth films with the a-axis normal to the surfaces yield tunnel junctions which exhibit Josephson-like behavior. Critical current modulation is observed in response to an applied magnetic field.