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
    Preparation of YBa2Cu3O7−x films and YBa2Cu3O7−x/Y2O3 multilayers using coevaporation and atomic oxygen (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 3096-3098 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Thin layers of YBa2Cu3O7−x (YBCO) deposited on LaAlO3 substrates have been prepared in situ by coevaporation of Y, Ba, and Cu. Incorporation of oxygen was accomplished by an atomic oxygen beam source with high cracking efficiency. The total oxygen flow at the substrate could be kept low enough to permit the use of a quadrupole mass spectrometer for evaporation rate monitoring. Films were strongly c-axis oriented with rocking curve full width at half-maximum values of 0.6°. Transport measurements on patterned films yielded critical current densities of 6×106 A/cm2 at 77 K. The deposition method was demonstrated to be feasible for preparation of Y2O3/YBCO heterostructures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.352995
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Thin-film growth and compositional effects in YBa2Cu3O7−x layers prepared by metalorganic chemical vapor deposition (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 4631-4642 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Thin-film growth and compositional effects of c-axis oriented YBa2Cu3O7−x (YBCO) thin films synthesized by metalorganic chemical vapor deposition have been investigated. The formation of single cation films using tetramethylheptanedionate precursors was shown to be mass controlled, exhibiting a ratio of deposited to evaporated species in the increasing order Ba, Y, and Cu. The physical properties of off-stoichiometric YBCO films deposited on MgO substrates were measured in the compositional range 1.1≤Ba/Y≤2.3 and 1.5≤Cu/Ba≤4.6. While structural properties such as c-axis values and rocking curves appeared unaffected to variations in cation stoichiometry, morphology was observed to be extremely sensitive even to slight changes in composition. Off-stoichiometric layers with Cu/Ba(approximately-greater-than)1.5 were observed to exhibit Cu-rich precipitates embedded in a 1:2:3 YBCO film matrix. The zero-resistivity temperatures were above 77 K for all cation film compositions measured. However, sharp ac-susceptibility transitions were restricted to a more narrow compositional range (1.9〈Cu/Ba〈3.6). The best superconducting properties [Tc=85 K, Jc (77 K)(approximately-greater-than)106 A/cm2] were observed for films with relatively rough surface morphologies (Ba/Y=1.6 and Cu/Ba=3.5). An optimum trade-off between smooth surfaces and superconducting properties was found for Ba/Y=1.5 and Cu/Ba=1.9, yielding Tc=81 K and Jc (77 K)=3×105 A/cm2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.354383
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The Role of Corticotropin-Releasing Factor in the Anxiogenic Effects of Ethanol Withdrawal (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 739 (1994), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1994.tb19819.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Free-choice responding for ethanol versus water in alcohol preferring (P) and unselected Wistar rats is differentially modified by naloxone, bromocriptine, and methysergide (1990)
    Springer
    Psychopharmacology 101 (1990), S. 178-186 
    Details
    ISSN: 1432-2072
    Keywords: Ethanol self-administration ; Bromocriptine ; Naloxone ; Methysergide ; Alcohol-preferring rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The role of opioids, dopamine and serotonin in ethanol (EtOH) reward and preference was investigated in non-deprived, Alcohol-Preferring (P), and genetically heterogenous Wistar rats. Operant responding for ethanol was initiated using sweet-solution substitution procedures. The rats were then trained in 30-min daily sessiosn to respond for ethanol (10% v/v) versus water under a two-lever, free-choice contingency. All testing was conducted in the absence of water and food deprivation or addition of sweeteners to the ethanol drinking solution. Rats of both strains developed stable preferences in responding for ethanol over water and consumed ethanol at quantities sufficient to produce pharmacologically relevant mean blood alcohol concentrations (P-Rats: 98±19.6 mg%; unselected Wistars: 41.7±8.5 mg%). InP-rats, systemic naloxone (NAL; 0.125, 0.25 and 0.5 mg/kg) pretreatments resulted in a dose-dependent suppression in responding for both ethanol and water, but did not alter ethanol preference (expressed as percent ethanol of total intake). In contrast, bromocriptine (BRO; 1.0, 2.0 and 4.0 mg/kg) produced a significant, dose-dependent shift in preference from ethanol toward water by inhibiting responding for ethanol while enhancing water consumption. Inunselected Wistar rats, NAL and BRO treatments produced changes in ethanol preference patterns similar to those observed in P-rats. However, compared to P-rats, these changes were smaller and not consistently dose dependent. No changes in ethanol preference and water or ethanol intake were observed with methysergide (MET; 2.5, 5.0, 10.0 mg/kg) in either strain of rat. Together, the results suggest a possible involvement of dopaminergic mechanisms in the reinforcing properties of ethanol. In contrast, the response decrements observed with naloxone may reflect a more general depression in consummatory behavior.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02244123
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Nuclear quadrupole interaction at133Ba (EC)133Cs in Eu1Ba2Cu3O7−° (1990)
    Springer
    Hyperfine interactions 61 (1990), S. 1151-1154 
    Details
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We studied the nuclear quadrupole interaction (NQI) at133Ba(EC)133Cs in Eu1Ba2Cu3O7–6 by time differential perturbed angular correlation between 11 K and 300 K. No anomalies in the NQI parameters around Tc were detected. All Ba sites appear to be identical and the precession frequency is ω=80(2) Mrad/s (assuming axial symmetry), independent of temperature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02407593
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Orientation of the main axis of the electric field gradient at the iron nucleus in some iron doped copper oxide compounds (1990)
    Springer
    Hyperfine interactions 55 (1990), S. 1261-1265 
    Details
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We have performed57Fe Mössbauer measurements on aligned iron-doped crystallites of La1.85Sr0.15CuO4−y and Pb2Sr2R0.50Cu3O8−y where R=Eu or Ho. From the intensity ratio of the two lines of the quadrupole doublets we deduce that the main axis of the electric field gradient does not coincide with thec axis of the lattice. This surprising result indicates that at the iron probe, substituted in the Cu site of the CuO2 plane, the local electric charge symmetry is different from the lattice symmetry. We discuss this result in relation with the electronic configuration nearby this Cu site. The Pb based samples without Ca are magnetic at room temperature. Therefore in these samples Ca plays the same role as Sr in (La, Sr)2CuO4−y .
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02397157
    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...