Experimental investigations of superconductivity in quasi-two-dimensional epitaxial copper oxide superlattices and trilayers
- Oak Ridge National Lab., TN (United States)
Epitaxial trilayer and superlattice structures grown by pulsed laser ablation have been used to study the superconducting-to-normal transition and ultrathin (one and two c-axis unit cells) YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} layers. The normalized flux-flow resistances for several epitaxial structures containing two-cell-thick YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} films collapse onto the `universal` curve of the Ginzburg-Landau Coulomb gas (GLCG) model. Analysis of normalized resistance data for a series of superlattices containing one-cell-thick YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} layers also is consistent with the behavior expected for quasi-two-dimensional layers in a highly anisotropic, layered three-dimensional superconductor. Current-voltage measurements for one of the trilayer structures also are consistent with the normalized resistance data, and with the GLCG model. Scanning tunneling microscopy, transmission electron microscopy, and electrical transport studies show that growth-related steps in ultrathin YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} layer affect electrical continuity over macroscopic distances, acting as weak links. However, the perturbation of the superconducting order parameter can be minimized by utilizing hole-doped buffer and cap layers, on both sides of the YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} layer, in trilayers and superlattices. 38 refs., 8 figs., 1 tab.
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 62428
- Report Number(s):
- CONF-9302103-; ISSN 0361-5235; TRN: 95:004351-001
- Journal Information:
- Journal of Electronic Materials, Vol. 23, Issue 9; Conference: 122. annual meeting of the Minerals, Metals and Materials Society (TMS), Denver, CO (United States), 21-25 Feb 1993; Other Information: PBD: Sep 1994
- Country of Publication:
- United States
- Language:
- English
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