LaAlO/sub 3/-YBCO multilayers

The authors describe the growth of HTS (high-temperature superconductor) bilayers (LaAlO/sub 3//YBa/sub 2/Cu/sub 3/O/sub 7/) and trilayers (YBa/sub 2/Cu/sub 3/O/sub 7//LaAlO/sub 3//YBa/sub 2/Cu/sub 3/O/sub 7/) using off-axis RF sputtering from single stoichiometric targets. TEM (transmission electron microscope) examination shows that both the LaAlO/sub 3/ and YBa/sub 2/Cu/sub 3/O/sub 7/ films grow epitaxially upon the preceding layer. The interfaces between layers and at the LaAlO/sub 3/ substrates are sharp and clean. It is found that deposition of the subsequent layers does not degrade the electrical properties of the bottom YBa/sub 2/Cu/sub 3/O/sub 7/ layer; this observation extends to the surface resistance and to the superconducting transition temperature of the bottom YBCO layer. The results of the electrical measurements of the multilayer structures made by the off- and on-axis LaAlO/sub 3/ depositions are discussed.