Epitaxial thin films and heterostructures of a copper‐oxide‐based isotropic metallic oxide (La8−xSrxCu8O20)

1995 ◽  
Vol 77 (10) ◽  
pp. 5449-5451 ◽  
Author(s):  
C. B. Eom ◽  
R. J. Cava ◽  
Julia M. Phillips ◽  
D. J. Werder
1995 ◽  
Vol 401 ◽  
Author(s):  
C. B. Eom

AbstractWe have grown epitaxial thin films of a new family of copper-oxide-based isotropic metallic oxides such as La6.4Sr1.6Cu8O20, La5BaCu6O13 and La6BaYCu8O20in situ by 900° off-axis sputtering. These metallic oxides are pseudo-cubic perovskites with essentially isotropic properties, which could be ideal normal metals for SNS junctions in superconducting devices. We have also grown epitaxial SNS superconducting heterostructures (c-axis YBa2Cu3O7 / La6.4Sr1.6Cu8O20 / c-axis YBa2Cu3O7) with a copper-oxide-based isotropic metallic oxide (La6.4Sr1.6Cu8O20) normal metal barrier. X-ray diffraction and cross-sectional transmission electron microscopy reveal these heterostructures to have high crystalline quality and clean interfaces. This material will facilitate fabrication of ideal SNS Josephson junctions with low boundary resistance due to its excellent chemical compatibility and lattice match with cuprate superconductors and will be useful for determining the source of interface resistance in such heterostructures.


1994 ◽  
Vol 341 ◽  
Author(s):  
C. B. Eom ◽  
Julia M. Phillips ◽  
R. J. Cava

AbstractWe have grown epitaxial thin films of various isotropic metallic oxides such as Sr1-xCaxRuO3 and La8-xSrxCu8O2Oin situ by 90° off-axis sputtering. These metallic oxides are pseudo-cubic perovskites with essentially isotropic properties, which could be ideal normal metals for SNS junctions in superconducting devices and for electrodes in ferroelectric devices. We have fabricated epitaxial ferroelectric heterostructures [SrRuO3/Pb(Zr0. 52 Ti0.4 8) O3 /SrRuO3] employing isotropic metallic oxide (SrRuO3) electrodes on substrates of (100) SrTiO3 and (100) Si with an yttria stabilized zirconia buffer layer. They exhibit superior fatigue characteristics over those made with metal electrodes, showing little degradation over 10 cycles, with a large remnant polarization (27 μC/cm2 ). We have also grown epitaxial superconducting heterostructures (YBa2Cu3O7 / La8-xSrxCu8O2O / YBa2Cu3O7 ) with a copper-oxide-based isotropic metallic oxide (La8-xSrxCu8O20) normal metal barrier. X-ray diffraction and cross-sectional transmission electron microscopy reveal these heterostructures to have high crystalline quality and clean interfaces. This material will facilitate fabrication of ideal SNS Josephson junctions with low boundary resistance due to its excellent chemical compatibility and lattice match with cuprate superconductors and will be useful for determining the source of interface resistance in such heterostructures.


1997 ◽  
Vol 474 ◽  
Author(s):  
Q. Gan ◽  
R. A. Rao ◽  
C.B Eom

ABSTRACTWe have grown epitaxial thin films of isotropie metallic oxide SrRuC>3 on both exact and vicinal (001) SrTiO3 substrates with miscut angle (α) up to 5.0° and miscut direction (β) up to 37° away from the in-plane [010] axis. The effects of both α and β on the epitaxial growth and domain structure of epitaxial SrRuC>3 thin films were studied by x-ray diffraction and atomic force microscopy (AFM). On vicinal SrTiO3 substrates with a large miscut angle (α = 1.7°, 2.0°, 4.1°, and 5.0°) and miscut direction close to the [010] axis, single crystal epitaxial (110)° SrRuO3 thin films were obtained. [The superscript o refers to the Miller indices based on the orthorhombic unit cell.] Decreasing the substrate miscut angle or aligning the miscut direction close to the [110] axis (β = 45°) resulted in an increase of 90° domains in the plane. The films grown on vicinal substrates displayed a significant improvement in crystalline quality and in-plane epitaxial alignment as compared to the films grown on exact (001) SrTiO3 substrates. AFM revealed that as the miscut angle increased the growth mechanism changed from two dimensional nucleation to step flow growth.


1997 ◽  
Vol 70 (22) ◽  
pp. 3035-3037 ◽  
Author(s):  
R. A. Rao ◽  
Q. Gan ◽  
C. B. Eom ◽  
R. J. Cava ◽  
Y. Suzuki ◽  
...  

CrystEngComm ◽  
2018 ◽  
Vol 20 (34) ◽  
pp. 5012-5016 ◽  
Author(s):  
Tomoya Onozuka ◽  
Akira Chikamatsu ◽  
Yasushi Hirose ◽  
Tetsuya Hasegawa

Herein, we investigated the domain morphologies of defect-perovskite LaCuOx (2.5 ≤ x ≤ 3.0) thin films grown on cubic SrTiO3 (100) and orthorhombic NdGaO3 (110) substrates by pulsed-laser deposition.


1997 ◽  
Vol 494 ◽  
Author(s):  
R. A. Rao ◽  
D. B. Kacedon ◽  
C. B. Eom

ABSTRACTWe have grown epitaxial ferromagnetic metallic oxide SrRuO3 thin films with different domain structures on (001) LaAlO3 and miscut (001) SrTiO3 substrates. The effect of crystallographic domain structures on the magnetization and magnetoresistive behavior of epitaxial SrRuO3 thin films has been studied. Magnetization measurements on the single domain film on 2° miscut (001) SrTiO3 substrate showed that the in-plane [110] direction, which is aligned along the miscut direction, is the easier axis for magnetization compared to the [001] direction. This film also showed a strong anisotropie magnetoresistance (AMR) effect of ∼ 8% in magnitude. In contrast, the SrRuO3 thin film on (001) LaAlO3 substrate shows identical magnetization and magnetoresistance behavior in two orthogonal directions on the film due to the presence of 90 domains in the plane. For both the films, large negative magnetoresistance effects (-10%) were observed when the current and the applied magnetic field are parallel. The magnetoresistance behavior is explained in terms of suppression of spin fluctuations near Tc and the AMR effect.


2021 ◽  
Vol 207 ◽  
pp. 116683
Author(s):  
Jun Young Lee ◽  
Gopinathan Anoop ◽  
Sanjith Unithrattil ◽  
WooJun Seol ◽  
Youngki Yeo ◽  
...  

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