OPTIMISATION OF YBa 2 Cu 3 O 7 THIN FILMS FOR MULTILAYERS

Thin films of YBa 2 Cu 3 O 7 have been grown “in situ” using e-beam evaporation. The electrical and structural properties of the films have been correlated with composition, oxygen environment, temperature and substrate type and orientation. When the composition is controlled with sufficient precision ( C >90K, J c >3 10 6 A/cm 2 at 77K) and smooth surfaces are reproducibly obtained. Fully epitaxial SIS trilayers of YBa 2 Cu 3 O 7 /Y 2 O 3 have been grown.