Strained single-crystal Al{sub 2}O{sub 3} grown layer by layer on Nb (110) thin films
- Department of Physics and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)
The authors report on the growth of single-crystal Al{sub 2}O{sub 3} thin films on Nb (110) surfaces. Niobium is grown on {alpha}-Al{sub 2}O{sub 3} (1120), followed by the evaporation of Al in an O{sub 2} background. Initially, Al{sub 2}O{sub 3} grows layer by layer with hexagonal symmetry indicating either {alpha}-Al{sub 2}O{sub 3} (0001) or {gamma}-Al{sub 2}O{sub 3} (111). Diffraction measurements show that the Al{sub 2}O{sub 3} initially grows clamped to the Nb with tensile strain near 10%. This strain relaxes with further deposition and beyond about 50 A ring , the authors observe island growth. Despite the asymmetric misfit between Al{sub 2}O{sub 3} and Nb, the strain is surprisingly isotropic. Josephson junctions employing epitaxial Al{sub 2}O{sub 3} show low effective tunnel barriers and high leakage currents.
- OSTI ID:
- 20971970
- Journal Information:
- Applied Physics Letters, Vol. 90, Issue 24; Other Information: DOI: 10.1063/1.2747675; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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