ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
Filter
  • Articles  (11)
  • YBCO  (11)
  • Springer  (11)
  • 1990-1994  (11)
  • 1950-1954
  • Electrical Engineering, Measurement and Control Technology  (11)
Collection
  • Articles  (11)
Source
Keywords
Publisher
  • Springer  (11)
Years
Year
Topic
  • Electrical Engineering, Measurement and Control Technology  (11)
  • Physics  (11)
  • 1
    Electronic Resource
    Electronic Resource
    DC SQUIDs based on YBCO step edge junctions (1993)
    Springer
    Journal of superconductivity 6 (1993), S. 391-395 
    Details
    ISSN: 1572-9605
    Keywords: YBCO ; dc SQUID ; high-T- c junction ; step edge junction ; Josephson effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract We describe the fabrication and testing of dc SQUIDs (Superconducting QUantum Interference Devices) obtained by photolithographic patterning of YBa2Cu3O7−x thin films deposited both on SrTiO3 and MgO substrates. The Josephson junctions in the superconducting loop are of the “step-edge” type, where the weak link is obtained through the growth of grains with different orientations across suitably prepared steps previously etched on the substrate surface. TheI−V characteristics of the devices tested show multiple branches and instabilities having a weak dependence on the external magnetic field, probably due to formation of junction clusters on the substrate step. The SQUID devices showed quantum interference behavior and an easily detectable voltage modulation with the applied magnetic field at a temperature of 77 K.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00617977
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Investigation of the dominant point defects in tetragonal YBa2Cu3Ox at elevated temperatures (1993)
    Springer
    Journal of superconductivity 6 (1993), S. 313-316 
    Details
    ISSN: 1572-9605
    Keywords: YBCO ; oxygen defects ; point defects ; superconductors ; tetragonal phase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The manner in which oxygen is incorporated into YBa2Cu3O x (YBCO) at ∼800°C for values ofx close to 6 is shown to be in the form of neutral oxygen interstitials, O i x . The experimental data on which this conclusion is based are obtained from measurements of oxygen partial pressure,P(O2), as a function of compositionx and temperatureT (5.99≤x≤ 6.35, 825≤T≤1120 K). The data are obtained by a solid-state electrochemical method. Other conclusions of this study include: (a) O i x are noninteracting forx ≃ 6. (b) The stoichiometric composition of YBCO isx ≃ 6.0. (c) The reaction enthalpy of oxidation is 179 kJ/mol O2. (d) The Fermi level changes by ≃ −0.2 eV asx increases from 6.05 to 6.35.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00617477
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Angular dependence of transport current near critical at fields to 4 T in metalorganic thin films (1994)
    Springer
    Journal of superconductivity 7 (1994), S. 303-308 
    Details
    ISSN: 1572-9605
    Keywords: Critical current ; high temperature superconductor ; thin film ; angular dependence ; magnetic field dependence ; YBCO ; metalorganic preparation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Values of the transport current have been obtained as a function of angle of the magnetic field to the plane of the thin film YBa2Cu3O7−d (YBCO) prepared by metalorganic deposition. Current flowed in thea, b planes at various angles to the applied magnetic fields to 4.2 T. Films with thicknesses near 350 nm were studied. For these thin films andH∥c a secondary maximum is observed whenJ c〉 1 MA/cm2. NearH∥a, b a large increase inI c is observed, and the sharpness, field dependence, and field directional dependence is discussed. The response to currents aboveI c is determined and the fit to a power lawV∼I n shows a strong correlation betweenI c andn.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00724558
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Effect of Ho addition on the properties of Y-system superconductors (1992)
    Springer
    Journal of superconductivity 5 (1992), S. 95-99 
    Details
    ISSN: 1572-9605
    Keywords: YBCO ; Ho addition ; critical current density
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract (YHo)Ba2Cu3O7−y is prepared by the powder melting process and its properties are investigated. It is found that Ho addition can change the melting temperature of a Y-system superconductor. TheJ c values of YBCO can be improved by Ho substitution, which is due to the effect of Ho addition on the number and quality of grain boundaries and the size and distribution of 211 particles. The highestJ c value was found to be 50,000 A/cm2 (77 K, 1T,H⊥I) in Y0.8Ho0.2Ba2Cu3O7−y. Our results indicate that the number and quality of grain boundaries have a great influence on the superconducting properties. A discussion is given on the relationship betweenJ c and the size and phase proportion of 211 particles. There are a lot of dense twins in the sample, and many crystal defects exist around the 211 phase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00618051
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Lithographic patterning of superconducting YBCO films (1992)
    Springer
    Journal of superconductivity 5 (1992), S. 445-449 
    Details
    ISSN: 1572-9605
    Keywords: YBCO ; microbridge ; lithography ; etching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Microbridges of YBa2Cu3O7 thin films have been fabricated by conventional photolithography and wet chemical etching using EDTA, and by the lift-off lithography technique. The variation of etch rate with etch time, etchant temperature, and post-deposition sintering temperature has been studied. It has been shown that both techniques are useful for film patterning. However, an additional sintering step is necessary for the chemically etched sample to regain the original film properties. An order of increase in critical current density is observed for the patterned film.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00620502
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Low-temperature critical field of YBCO (1994)
    Springer
    Journal of superconductivity 7 (1994), S. 269-270 
    Details
    ISSN: 1572-9605
    Keywords: YBCO ; high field ; critical field ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract We have measured the upper critical fieldH C2(T) of YBa2Cu3O7 (YBCO) thin films in magnetic fields up to 140 T forH applied parallel to thec-axis of the film. The critical field in the zero-temperature limit is 138 T, and the temperature dependence does not fit any simple model.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00724550
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Microstructures of high-J c melt-textured YBa2Cu3O7−x /Ag superconductors (1994)
    Springer
    Journal of superconductivity 7 (1994), S. 947-950 
    Details
    ISSN: 1572-9605
    Keywords: Critical current density ; Ag addition ; grain alignment ; flux pinning ; defect structure ; YBCO ; melt-texturing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Silver has been previously added to the melt-textured YBa2Cu3O7−x in order to increase the critical current density (J c ) of these materials. However, the effect of this addition on theJ c is presently unclear. The purpose of this study is to investigate the effect of silver on both critical current density and the microstructure of the melt-textured YBa2Cu3O7−x superconductors by means of X-ray diffraction, optical polarized microscopy, and transmission electron microscopy (TEM). TheJ c of the MTG YBCO/Ag samples is more than 104A/cm2 under the 5 kOe magnetic field. It has been shown that as the concentration of silver increases, the fraction of the 211 phase dispersed within the 123 matrix decreases. Therefore, theJ c slightly decreases. These results, together with the effect of the 211 phase, dislocations, and other structure defects on flux pinning, are described in this paper.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00732277
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Specific heat of YBa2Cu3O7 (1994)
    Springer
    Journal of superconductivity 7 (1994), S. 251-255 
    Details
    ISSN: 1572-9605
    Keywords: Specific heat ; impurity ; defects ; YBCO ; superconducting volume fraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Specific heat measurements, including measurements in magnetic fields and at both low temperatures and nearT c , on a number of YBa2Cu3O7 samples have revealed several correlations among strongly sample-dependent parameters. These correlations suggest that the sample dependence of the parameters reflects a sample dependence of the volume fraction of superconductivity, which is in turn correlated with a low concentration of Cu2+ moments. The correlations give a criterion for recognizing the values of the parameters characteristic of the fully superconducting material. Preliminary results on the effects of sample heat treatment are reported. New data on the “linear term” is presented and discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00730406
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Absorption and emission spectra of the YBCO laser plume (1994)
    Springer
    Journal of superconductivity 7 (1994), S. 823-828 
    Details
    ISSN: 1572-9605
    Keywords: YBCO ; laser plume ; emission spectroscopy ; absorption spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The plasma produced during laser ablation deposition of thin film YBCO has been studied by optical emission spectroscopy. There is evidence of increased YO band emission in the range 590–625 nm as the ambient oxygen gas pressure confining the plume is increased in the range 30–200 m Torr. Temporal profiles show that close to the target the plume is insensitive to ambient oxygen pressure. It is deduced that the optical emission here is excited by electron impact excitation. Further away from the target there is evidence that two distinct processes are at work. One is again electron excitation; the emission from this process decreases with distance because the expanding plume cools and collisions become less frequent in the expanding gas. The second is driven by oxidation of atomic species expelled at high speeds from the target. The main region of this activity is in the plume sheath where a shock front ensures heating of ambient O2 and reaction of monatomic plasma species to form oxide in an exothermic reaction. Spatial mapping of the emission demonstrates clearly how increasing oxygen gas pressure confines the plasma and enhances the emission intensity from the molecular YO species ejected from the target in a smaller region close to the target. Ba+ is observed as a dominant species only very close to (within 1 mm of) the target. Absorption spectra have been taken in an attempt to examine ground state and cool species in the plume. They reveal the quite surprising result that YO persists in the chamber for periods up to 1 msec. This suggests an explanation for the recent report of off-axis laser deposition in terms of simple condensation. Previously, quasi-ballistic transfer of material from target to substrate has been considered the only significant process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01320877
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Symmetry of the pairing state in the high-T c oxides (1994)
    Springer
    Journal of superconductivity 7 (1994), S. 865-869 
    Details
    ISSN: 1572-9605
    Keywords: Symmetry of the pairing ; gaplessness ; YBCO ; cuprates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract There are conflicting experimental data related to the symmetry of the order parameter in cuprate superconductors. Our previously developed concept, which contains unusuals-wave pairing with a two-gap spectrum, energy gap anisotropy, and gaplessness for a nonstoichiometric state, provides a unified and consistent description of experimental data related to the symmetry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01320884
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Anisotropy of optical constants of YBCO (1994)
    Springer
    Journal of superconductivity 7 (1994), S. 943-946 
    Details
    ISSN: 1572-9605
    Keywords: YBCO ; optical constants ; attenuated total reflection ; ellipsometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Otto configuration attenuated total reflection (ATR) measurements of the excitation of surface plasmons in the infrared have been carried out on YBCO films deposited on MgO (100) substrates. The dielectric constants for YBCO at 3.392μm are determined to be −10+15i forc-axis material. The anisotropic nature of the cuprate is seen from films with other orientations: nearlya-axis material has constants of 4.0+7.0i. It is thus not metallic in its optical response along thec-axis which lies parallel to the substrate plane. Ellipsometric measurements in the visible onc-axis material point to a maximum surface plasmon energy of 1 eV.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00732276
    Location Call Number Expected 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...