Title :
Epitaxial Sr/sub 2/RuO/sub 4/ heterostructures
Author :
Madhavan, S. ; Ying Liu ; Schlom, D.G. ; Dabkowski, A. ; Dabkowska, H.A. ; Suzuki, Y. ; Takeuchi, I. ; Trajanovic, Z. ; Sharma, R.P.
Author_Institution :
Pennsylvania State Univ., University Park, PA, USA
fDate :
6/1/1997 12:00:00 AM
Abstract :
Sr/sub 2/RuO/sub 4/ is the only known layered perovskite that is free of copper, yet superconducting. Its low metallic resistivity and excellent lattice match with YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// make it an attractive candidate for use as conductive electrodes to YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta//-based superconducting devices or as a normal metal in YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta//-based SNS junctions. We have determined optimal deposition conditions for growth of single-domain epitaxial films of Sr/sub 2/RuO/sub 4/. Films with excellent crystallinity are readily grown at substrate temperatures exceeding 1000/spl deg/C at low pressures. At lower temperatures and higher pressures, films predominantly consist of the SrRuO/sub 3/ phase. Resistivity versus temperature measurements reveal that the as-grown Sr/sub 2/RuO/sub 4/ films are metallic, but not superconducting. Epitaxial YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta///Sr/sub 2/RuO/sub 4/ heterostructures have also been grown. X-ray and resistivity measurements show that the YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// films are of high quality.
Keywords :
X-ray diffraction; barium compounds; electrical resistivity; electrodes; high-temperature superconductors; magnetisation; metallic epitaxial layers; pulsed laser deposition; ruthenium compounds; strontium compounds; superconducting epitaxial layers; yttrium compounds; 1000 degC; Sr/sub 2/RuO/sub 4/; SrRuO/sub 3/; SrRuO/sub 3/ phase; X-ray measurements; YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta//-based SNS junctions; YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta//-based superconducting devices; YBa/sub 2/Cu/sub 3/O/sub 7/; conductive electrodes; epitaxial Sr/sub 2/RuO/sub 4/ heterostructures; epitaxial YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta///Sr/sub 2/RuO/sub 4/ heterostructures; excellent crystallinity; excellent lattice match; growth; high quality YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// films; low metallic resistivity; low pressures; magnetic measurements; magnetization; metallic as-grown Sr/sub 2/RuO/sub 4/ films; normal metal; optimal deposition conditions; pulsed laser deposition; single-domain epitaxial films; substrate temperatures; superconducting layered perovskite; temperature dependence; Conductivity; Copper; Crystallization; Electrodes; Lattices; Strontium; Superconducting devices; Superconducting epitaxial layers; Superconducting films; Temperature;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
