Search Results - (Author, Cooperation:J. Carolan)

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  1. 1
    Staff View
    Publication Date:
    2015-07-15
    Publisher:
    American Association for the Advancement of Science (AAAS)
    Print ISSN:
    0036-8075
    Electronic ISSN:
    1095-9203
    Topics:
    Biology
    Chemistry and Pharmacology
    Computer Science
    Medicine
    Natural Sciences in General
    Physics
    Published by:
    http://www.aaas.org/

    Latest Papers from Table of Contents or Articles in Press
  2. 2
    Wong, A. S. ; Ma, Q. Y. ; Dosanjh, P. ; Carolan, J. F. ; Hardy, W. N.

    [S.l.] : American Institute of Physics (AIP)
    Published 1995
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Infinite layer Ca1−xSrxCuO2 (CSCO) films, grown by pulsed laser deposition with x=0.66 and 0.9, were doped by implanting O+ ions with an accelerating energy of 70 keV and a dose of 3×1016 cm−2. The resistivity of the films, in the temperature range 4–200 K, decreased by over two orders of magnitude compared with the original as-grown film. Annealing the as-grown films in an atmosphere of O2 at 500 °C resulted in only a factor of 2 decrease in this temperature range. A magnetic anomaly resembling a diamagnetic transition was observed in the 85–90 K range in implanted films which was not observed in as-grown films. A comparison of the properties of implanted films, before and after annealing, suggest that increased oxygen content alone is not responsible for the observed changes, and thus defect creation resulting from implantation may also play a significant role. © 1995 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.360317

    Articles: DFG German National Licenses
  3. 3
    Ma, Q. Y. ; Dosanjh, P. ; Entin, I. ; Liang, R. ; Carolan, J. F. ; Hardy, W. N.

    [S.l.] : American Institute of Physics (AIP)
    Published 1994
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Films of the infinite layer compound Ca1−xSrxCuO2 have been grown on SrTiO3 substrates by pulsed laser ablation deposition. The properties of the films depend strongly on the processing temperature. Between 650–700 °C the films are epitaxial with the c axis oriented normal to the surface of the substrates. The surfaces of the films are smooth, as indicated by scanning electron microscopy. Films processed at temperatures above 740 or below 600 °C are polycrystalline. X-ray diffraction patterns show that the c-axis lattice constant varies from 3.23 A(ring) for x=0.10, to 3.39 for x=0.66 and 3.43 A(ring) for x=0.90. Electrical measurements show the films to have a semiconducting behavior; no diamagnetic transition was observed in these films.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.356159

    Articles: DFG German National Licenses
  4. 4
    Sullivan, Brian T. ; Osborne, N. R. ; Hardy, W. N. ; Carolan, J. F. ; Yang, B. X. ; Michael, P. J. ; Parsons, R. R.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1988
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Thin films of the high-temperature superconductor Bi-Sr-Ca-Cu-oxide were deposited by dc magnetron sputtering onto various substrates. Films deposited on (100) MgO substrates achieved zero resistance between 78 and 82.5 K depending upon the annealing conditions. The best films were produced with a quick post-anneal in oxygen at 870 °C followed by a slower anneal in air at the same temperature. The composition of the sputtered films was uniform within ±3% over an area 40 mm in radius, and films deposited at 15 and 40 mm from the center of deposition both exhibited high Tc transitions.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.99598

    Articles: DFG German National Licenses
  5. 5
    Närger, U. ; Hayden, M. E. ; Booth, J. L. ; Hardy, W. N. ; Whitehead, L. A. ; Carolan, J. F. ; Balzarini, D. A. ; Wishnow, E. H. ; Blake, C. C.

    [S.l.] : American Institute of Physics (AIP)
    Published 1990
    Staff View
    ISSN:
    1089-7623
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Electrical Engineering, Measurement and Control Technology
    Notes:
    We have developed a low cost continuous flow labyrinth calorimetric system which attains 0.3% accuracy in absolute energy balance and has a minimum sensitivity of 20 mW. This system is ideally suited to measure the energy balance of electrolytic reactions for output powers ranging from 0 to at least 25 W. By employing a catalyst to recombine the gaseous reaction products, the electrolysis cell can be operated as a closed system, thus eliminating many uncertainties associated with calorimetric measurements on open cell electrolytic processes. Careful calibrations using different electrical heater configurations inside the calorimeter demonstrate insensitivity to temperature gradients and local heating. We present measurements of energy balances of electrolytic reactions using Pd and Pt cathodes in 0.1 M LiOD in D2O as electrolyte. No anomalies are observed in the energy balance of either sample.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.1141161

    Articles: DFG German National Licenses
  6. 6
    Ma, Q. Y. ; Wong, A. ; Dosanjh, P. ; Carolan, J. F. ; Hardy, W. N.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1994
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    We present a novel technique for patterning high-temperature superconducting (HTS) film and multilayer device structures. In the process an impurity ion (e.g., Si) is implanted into HTS films through a photoresist mask. The impurity ions convert the irradiated portion of the film into an insulating form by chemical reaction between the ions and the oxygen in the film, without altering the overall crystalline structure of the film. Removal of the photoresist results in a flat surface, which allows the epitaxial growth and implantation patterning of subsequent films so that a complete multilayer device structure can be fabricated. We show in detail the patterning process, as well as the properties of patterned and regrown films. Some simple device structures, such as a vertical contact and a crossover, are demonstrated.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.112613

    Articles: DFG German National Licenses
  7. 7
    Ma, Q. Y. ; Dosanjh, P. ; Carolan, J. F. ; Hardy, W. N.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1993
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    A method of converting an oxide Y-Ba-Cu-O (YBCO) film from superconducting into insulating film is presented. With implanted Si ions, the film loses its electrical conductivity and diamagnetism while its crystalline structure is preserved. The process allows the growth of an epitaxial YBCO film on top of the inhibited area, thus providing an effective method of patterning high temperature superconducting multilayer structures.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.110072

    Articles: DFG German National Licenses
  8. 8
    Wong, André ; Liang, Ruixing ; Badaye, M. ; Carolan, J. F. ; Hardy, W. N.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1997
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Magnesium ions were implanted into highly crystalline YBa2Cu3O7 (YBCO) thin films for the purpose of patterning. Films were implanted at doses corresponding to Mg contents of x=0.008, 0.02, and 0.04 in the formula YBa2(Cu1−xMgx)3O7. High temperature annealing (900 °C) of films implanted below the solubility limit was successful in obtaining single phase, Mg doped YBCO films with finite resistivities at 77 K and x-ray (005) rocking curve widths 〈0.15°. An electron probe microanalysis on a film patterned using Mg implantation revealed that lateral diffusion of Mg ions resulting from annealing was limited to only a few microns. The superior quality of a top layer film indicated that Mg ion implantation is suitable for multilayer patterning. © 1997 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.120489

    Articles: DFG German National Licenses
  9. 9
    Staff View
    ISSN:
    0921-4534
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    http://linkinghub.elsevier.com/retrieve/pii/0921-4534(89)90965-9

    Articles: DFG German National Licenses
  10. 10
    Staff View
    ISSN:
    1615-5947
    Keywords:
    Veins ; lasers ; ulcers ; venous
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Medicine
    Notes:
    Abstract Management of intractable venous ulceration remains an unrewarding task which is increasingly delegated to the realm of the vascular surgeon. The purpose of this pilot study was to assess the ulcer-healing effects of the newest form of biostimulation—the low power laser. Twelve patients with chronic venous ulcers unresponsive to conservative measures were treated with infrared laser irradiation for twelve weeks. Two ulcers healed completely and there was a 27% (p〈0.01) reduction in size of the remaining ulcers. Treatment resulted in a 44% (p〈0.01) increase in ulcer floor area occupied by healthy granulation tissue. The most dramatic effect of laser treatment was the reduction in ulcer pain, from 7.5 to 3.5 (linear analogue scale) (p〈0.001). Laser irradiation had no effect on TcPO2, number of skin capillaries or pericapillary fibrin deposition in the lipodermatosclerotic area around the ulcer. The results of this pilot study are encouraging and a carefully controlled randomized study is indicated to compare low power laser irradiation to conventional treatment in the management of venous ulcers.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF02001375

    Articles: DFG German National Licenses
  11. 11
    Staff View
    ISSN:
    1572-9540
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract We update our muon spin relaxation studies of the magnetic field penetration depth which show the correlations betweenT c and the relaxation rate σ αn s/m * (carrier density/effective mass) of hole-doped high-T c cuprate superconductors (La2, Sr3)CuO4, YBa2Cu3O7 (Y1−xPrx)Ba2Cu3O7, and other double and triple layer systems. These studies are extended to the organic superconductor (BEDT-TTF)2Cu(NCS)2.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF02395995

    Articles: DFG German National Licenses
  12. 12
    Staff View
    ISSN:
    1572-9540
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract We have searched for anomalous internal magnetic fields in highT c materials which are predicted to occur in anyon and flux phase models of superconductivity. The magnitude, anisotropy and temperature dependence of the observed fields inc-axis oriented samples of sintered YBa2CuO3O7 and of thick-film Bi2Sr2CaCu2O8 are consistent with a conventional nuclear dipolar origin. An upper limit of ≲0.08 mT is set for any anomalous magnetic fields along thec-axis atμ + sites in bulk CuO2 superconductors.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF02395996

    Articles: DFG German National Licenses
  13. 13
    Staff View
    ISSN:
    1572-9540
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract We report precision transverse fieldμSR measurements of the internal field distribution in the vortex state of crystalline YBa2Cu3O6.95. A novel low background apparatus was used to study a mosaic sample of three high quality single crystals (Tc=93.3K). The observed frequency spectra in magnetic fields of 5kG and 15 kG applied along the c-axis have the characteristic features expected for a regular vortex lattice with some additional broadening. From a preliminary analysis we find that [λ(0)/λ(T)]2 has a linear temperature coefficient forT〈30 K. Such a term is inconsistent with simple s-wave pairing in the superconducting state. These results support recent microwave measurements ofλ(T) on similar crystals in zero applied field but differ significantly from previousμSR reports on sintered powders and crystals with lower Tc.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF02068944

    Articles: DFG German National Licenses
  14. 14
    Staff View
    ISSN:
    1572-9540
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract A combination of μSR and17O nuclear quadrupolar μLCR has been used to obtain detailed information on the muon site in YBa2Cu3O7. The rms magnitude of the nuclear dipolar fields in YBa2Cu3O7 enriched with 38%17O is about twice that in the natural16O sample. In addition the17O μLCR spectrum shows that the electric field gradient tensor at the oxygen closest to the muon is almost equal to that measured by NMR for the CuO2 plane sites O(2,3). These results suggest that the muon in fully oxygenated YBa2Cu3O7 is located at a single site 1.0 Å from an oxygen ion, probably O(2,3).
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF02396001

    Articles: DFG German National Licenses