Properties of YBa/sub 2/Cu/sub 3/O/sub 7/ thin films deposited on substrates and bicrystals with vicinal offcut and realization of high I/sub c/R/sub n/ junctions

Poppe, U.; Divin, Y.Y.; Faley, M.I.; Wu, Jinsong; Jia, Chun‐Lin; Shadrin, P.M.; Urban, K.

doi:10.1109/77.919884

Cited by 56 publications

(36 citation statements)

References 12 publications

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“…All our SPM data confirm that the roughness of a 250 nm thick YBaCuO tilted film on sapphire is 1.5 times less than those of 100 nm thick films on tilted SrTiO 3 and NdGaO 3 substrates. 9,10 The roughness increases with increasing thickness and the difference in roughness should be even higher in favor of our films on sapphire if equal film thicknesses were considered. We can conclude that a low roughness adds to the advantages of tilted sapphire substrates.…”

Section: Film Deposition Characterization and Junction Patterningmentioning

confidence: 99%

THz Josephson properties of grain boundary YBaCuO junctions on symmetric, tilted bicrystal sapphire substrates

Stepantsov

Tarasov

Kalabukhov

et al. 2004

Journal of Applied Physics

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Superconducting Josephson junctions with high characteristic voltages (I c R n larger than 4 mV at 4.2 K) are fabricated by depositing YBa 2 Cu 3 O 7−x on tilted sapphire bicrystal substrates, where the tilting axis is along the grain boundary. The good junction quality and low microwave losses in sapphire gave high frequency response well into the THz region. High quality YBa 2 Cu 3 O 7−x epitaxial films were deposited on tilted sapphire substrates with CeO 2 buffer layers by pulsed laser deposition. YBaCuO films have smaller tilt angles, from 1.0°up to 10.3°, compared to inclination angles of the substrates from 1.5°to 13.6°. X-ray diffraction shows only a single orientation of the films in the a-b plane, as well as an absence of a-axis particles and outgrowths. Critical temperatures as high as T c = 88.5− 89.0 K and ⌬T c ഛ 1.5 K were obtained in all films. The grain boundary in a common high-T c superconducting junction is usually much less straight than in the in-plane rotated bicrystal substrate, depressing Josephson currents. The waviness of the artificial grain boundary in a tilted bicrystal film is three times less than in an in-plane (untilted) bicrystal. Tilted Josephson junctions of widths from 1.5 to 6 µm were tested at temperatures from 0.26 to 77 K. I c R n products as high as 4.5 mV were observed at T = 4.2 K. Shapiro steps were observed at voltages over 3 mV under 300 GHz irradiation. Josephson radiation from the tilted junction was measured at frequencies up to 1.7 THz by a cryogenic bolometer. Suppressing the critical current with a magnetic field can separate Josephson radiation and thermal radiation. A parabolic dependence of the response on bias voltage for thermal radiation corresponds to an increase of junction temperature from 260 mK at zero bias to 3 K at 1 mV bias.

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Section: Film Deposition Characterization and Junction Patterningmentioning

confidence: 99%

THz Josephson properties of grain boundary YBaCuO junctions on symmetric, tilted bicrystal sapphire substrates

Stepantsov

Tarasov

Kalabukhov

et al. 2004

Journal of Applied Physics

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“…[4][5][6][7] At this stage, few studies on the structural and transport properties of JJs generated on substrates tilted around a-b planes have been presented. 8,9 The properties of these geometries have been more extensively studied in JJs fabricated by a biepitaxial technique which has shown to be a good option for the implementation of a reliable technology based on the Joshepson effect. [10][11][12] The structure of the barrier depends on many factors like the misorientation angle between the two electrodes, the orientation of the interface plane with respect to crystallographic axes, and the meandering at the barrier, so no prediction of the exact boundary structure is possible.…”

Section: Introductionmentioning

confidence: 99%

Capacitance of Josephson junctions made on bicrystalline substrates of different geometries

et al. 2005

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“…Thus, for RBJ it is known that the magnitude of characteristic voltage V c varies slightly in a large range of misorientation angles up to 633 , while normal resistance at the same time can increase by an order of magnitude. 38 Note that when a ¼ 645 the current j c is strongly suppressed, and V c is reduced by an order of magnitude reaching 0.5 mV at liquid-helium temperature. 39 For TBJ the experiment revealed a much stronger angular dependence: with increasing misorientation angle by 6 the parameter V c decreased by more than three times.…”

Section: B Electrophysical Properties Of Bicrystal Junctionsmentioning

confidence: 98%

Josephson effect in cuprate superconducting structures

Ovsyannikov

Constantinian

2012

Low Temperature Physics

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Electron transport and microwave properties of cuprate superconducting structures (bicrystal junctions and hybrid mesa heterostructures) are discussed here. Superconducting current in junctions from cuprate superconductors with the dominant dx2−y2-wave symmetry is determined by the barrier properties, characterized by the mid-gap bound states due to the multiple Andreev reflection. In bicrystal junctions it is revealed via linear dependence of critical current density on square root of the transparency, and an increase of spectral density of shot noise at low voltages are observed. The experiments demonstrate that the superconducting hybrid mesa-heterostructures have the critical current density jс = 1–700 A/cm2 for an antiferromagnetic interlayer with thickness dM = 10–50 nm and the characteristic decay length of superconducting correlations on the order of 7 nm, due to the anomalous long range proximity effect, analyzed in the model of coupled superconductors via multilayer magnetic layer with antiferromagnetic ordering of magnetization in the layers. It is found that the hybrid mesa–heterostructures have much greater sensitivity to external magnetic field than conventional Josephson junctions because of the strong dependence of superconducting current on interlayer spin state.

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Properties of YBa/sub 2/Cu/sub 3/O/sub 7/ thin films deposited on substrates and bicrystals with vicinal offcut and realization of high I/sub c/R/sub n/ junctions

Cited by 56 publications

References 12 publications

THz Josephson properties of grain boundary YBaCuO junctions on symmetric, tilted bicrystal sapphire substrates

THz Josephson properties of grain boundary YBaCuO junctions on symmetric, tilted bicrystal sapphire substrates

Capacitance of Josephson junctions made on bicrystalline substrates of different geometries

Josephson effect in cuprate superconducting structures

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