Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Film thickness dependence of microwave surface resistance for YBa2Cu3O7 thin films (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 5295-5297 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Microwave surface resistance close to 10 GHz has been measured as a function of temperature for epitaxial thin films of YBa2Cu3O7 (YBCO) on LaAlO3 in the film thickness range of 0.2–0.8 μm. The films were made by a reduced-temperature post-anneal technique. The surface resistance (Rs) scaled to 10 GHz decreases with increasing film thickness as is expected due to the finite film thickness with respect to the magnetic penetration depth. Below about 70 K there is an increase in Rs for the thickest films, attributed to a change in microstructure from c axis normal to the substrate plane, to c axis in the plane of the substrate; the resulting minimum in Rs occurs at a film thickness of 0.6 μm. The critical current density (Jc) at 77 K is highest for the thinner films, so that films with the highest Jc do not have the lowest measured Rs. These results suggest that the optimum YBCO film thickness for microwave devices patterned from these films may be about 0.6 μm, depending on operating temperature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.353764
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Microwave surface resistance of YBa2Cu3O7 thin films on LaAlO3 substrates (1990)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 68 (1990), S. 2514-2516 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The surface resistance Rs of YBa2Cu3O7 (YBCO) thin films (0.6±0.1 μm) deposited onto 2.5-cm diam (100) LaAlO3 substrates has been measured at 22 GHz using both Cu and Nb cavities. The surface resistance falls precipitously at the superconducting transition (Tc =90 K) from a normal state value of approximately 2 Ω to a 77 K value of 13.7±1 mΩ, which is 1.6 times lower than Cu. At 4 K the surface resistance is 1±0.1 mΩ, as measured in a Nb superconducting cavity, which is an order of magnitude lower than Cu. The critical current density at 77 K is 4.5×104 A/cm2. Pole figure analyses show the ratio of c-axis to a-axis-oriented material in the film is 2.4:1. YBCO films deposited onto either LaGaO3 or LaAlO3 substrates with varying c/a ratios yield surface resistance values at 77 K that are crudely correlated with Rs. Therefore, the principal effect of orienting the material is to improve the sharpness of the high-frequency superconducting transition, consistent with the notion that the sharpness is associated with intergranular rather than intragranular properties.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.346493
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Lower temperature post-annealing of thin films of YBa2Cu3O7 at lower oxygen partial pressure (1991)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 58 (1991), S. 417-418 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Thin films of YBa2Cu3O7 formed by ambient temperature deposition and furnace post-annealing have been obtained at annealing temperatures around 750 °C and an oxygen partial pressure of 29 Pa. The zero resistance transition temperature of these smooth films on LaAlO3 was 89 K, and a critical current density in excess of 1 MA cm−2 at 77 K was found by transport measurements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.104654
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Epitaxial growth and critical current density of thin films of YBa2Cu3O7−x on LaAlO3 substrates (1989)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 54 (1989), S. 2719-2721 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Thin films of the high-temperature superconductor YBa2 Cu3 O7−x have been produced on (100) LaAlO3 substrates by coevaporation and furnace annealing. A 14-μm-wide and 400-μm-long constriction patterned on a 0.8-μm-thick film had a zero resistance transition temperature of 90 K, a transition width of 1.5 K, and a critical current density of 8×104 A cm−2 at 77 K. Although x-ray diffraction shows a definite c-axis alignment normal to the substrate plane, further analysis reveals that c-axis alignment in the substrate plane is also present. The detailed microstructural picture is revealed by transmission electron microscopy: a continuous layer, about 0.2 μm thick adjacent to the substrate, with c axis normal to the substrate plane, and the remaining top portion of the film, with the c axis in the film plane. In spite of the bilayer structure, the film remains epitaxial (the axes of the superconductor are parallel to the 〈100〉 directions of the substrate).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.101549
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Thickness and annealing dependence of the superconducting transition temperature of YBa2Cu3O7−x thin films on oxidized silicon and polycrystalline alumina substrates (1988)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 53 (1988), S. 2566-2568 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Superconducting thin films of YBa2Cu3O7−x in the thickness range of 0.2–0.9 μm were tested in this study. A zirconia buffer layer was used to minimize interdiffusion on oxidized silicon and polycrystalline alumina substrates. The highest zero resistance transition temperatures (85 K for oxidized silicon and 86 K for polycrystalline alumina) were obtained for the thicker films; these are the highest values reported for thin films of this superconductor on these substrates. The thickness and annealing dependence of the transition temperature suggests that interdiffusion limits the performance of the thinner samples.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.100533
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Y-Ba-Cu-O superconducting thin films by simultaneous or sequential evaporation (1988)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 52 (1988), S. 584-586 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Superconducting thin films of Y-Ba-Cu-O near the 1:2:3 stoichiometry were produced by simultaneous (coevaporation) and sequential (multilayer) evaporation in the same evaporator. The best film obtained on yttria-stabilized zirconia (YSZ) had a superconducting onset temperature of 104 K, a midpoint Tc of 92 K, and zero resistance at T≤74 K. Stoichiometry was deduced by inductively coupled plasma emission spectroscopy, and elemental depth profiles were obtained by x-ray photoelectron spectroscopy. Film stoichiometry changes only near the film/substrate boundary for films on YSZ. Films on Si/SiO2 were not superconducting; depth profiling shows severe changes of film composition with depth. A major theme of this work is process reproducibility, which was found to be poor for coevaporation but improved considerably for sequential evaporation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.99373
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Thin films of Y-Ba-Cu-O on silicon and silicon dioxide (1988)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 52 (1988), S. 1185-1186 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Thin films of the high-temperature superconductor Y-Ba-Cu-O near the 1:2:3 stoichiometry were deposited on single-crystal silicon and oxidized silicon with a zirconia buffer layer. Zero-resistance transition temperatures up to 83 K have been measured on the films formed by a process of sequential evaporation and furnace annealing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.99670
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Characterization of thin films of Y-Ba-Cu-O on oxidized silicon with a zirconia buffer layer (1988)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 52 (1988), S. 2068-2070 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Thin films of the high-temperature superconductor Y-Ba-Cu-O with zero-resistance transition temperatures up to 83 K have been recently reported by using a zirconia buffer layer on the primary materials of interest for electronics, Si and SiO2. In this letter, various characteristics of these films are discussed. Microstructural analysis using transmission electron microscopy shows the complex morphology of the unoriented polycrystalline films. Elemental depth profiling by x-ray photoelectron spectroscopy shows the effectiveness of the zirconia buffer layer in preventing interdiffusion; fluorine is found throughout the film at an abundance of 4 at. % The critical current density was measured as a function of temperature; its value is 5 kA cm−2 at 4.2 K.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.99749
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Thermal fluctuation and 1/f noise in oriented and unoriented Y1Ba2Cu3O7−x films (1989)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 55 (1989), S. 2233-2235 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report on electrical noise measurements made on YBCO (Y1 Ba2 Cu3 O7−x ) films on SrTiO3 , on bulk silicon with a ZrO2 buffer layer, and on thin dielectric membranes. We have found that 1/f noise predominates in the unoriented films and that thermal fluctuation noise is the chief source of noise in good films on SrTiO3 .
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.102355
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Superconducting thin films of Bi-Ca-Sr-Cu-O by sequential evaporation (1988)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 53 (1988), S. 327-328 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Thin films of the high-temperature superconductor Bi-Ca-Sr-Cu-O have been produced by sequential evaporation and furnace annealing. Zero-resistance transition temperatures are near 70 K, with an onset temperature of about 85 K, which corresponds to transition temperatures measured on bulk samples of this superconductor. X-ray analysis reveals that the superconducting phase identified by others from single-crystal studies is present in these films, and that the films are highly oriented, with the c axis perpendicular to the MgO substrate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.99907
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...