EPITAXIAL DEPOSITION AND PROPERTIES OF BI2SR2CACU2O8+DELTA BI2SR2YCU2O8+DELTA/BI2SR2CACU2O8+DELTA TRILAYERS/

We have deposited Cu2O8+delta/Bi2Sr2YCu2O8+delta/Bi2Sr2CaCu2O8+delta ( 2212/22Y2/2212) heterostructures by an in situ de sputtering technique at high oxygen pressures on (001) SrTiO3 substrates. The formation of highly c-axis oriented trilayers with sharp interfaces is demonstrate d by x-ray diffraction and transmission electron microscope (TEM) anal ysis. Both the top and the bottom 2212 layers are superconducting belo w 87 K. Tunneling phenomena on junctions fabricated from these trilaye rs are observed. The conductance versus voltage curves at low temperat ures exhibit a change of slope indicative of a gap structure at about 30 mV, a zero-bias peak, as well as linear background at high voltages . (C) 1996 American Institute of Physics.