Browsing Τμήμα Μηχανικών Μηχανολογίας και Κατασκευαστικής / Department of Mechanical and Manufacturing Engineering by Author "Ginsberg, D. M."
Now showing items 1-20 of 23
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Anisotropy of the optical dielectric function in the ab plane for YBa2Cu3O7-
Kotz, A. L.; Klein, M. V.; Lee, W. C.; Giapintzakis, John; Ginsberg, D. M.; Veal, B. W. (1992)We report ellipsometric measurements from surfaces of three single-crystal samples of YBa2Cu3O7. Two of the samples were untwinned with Tc=90 and 66 K. The third sample was a tetragonal single crystal with low oxygen content ...
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Anisotropy of the resistivity in the a-b plane of a superconducting YBa2Cu3O7-δ single crystal
Kim, J.-T.; Giapintzakis, John; Ginsberg, D. M. (1996)We have measured the in-plane longitudinal resistivities pa and pb as functions of temperature and magnetic field. The measurements were all made on the same detwinned single crystal of YBa2Cu3O7-δ (YBCO). Defining Tc to ...
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Constraints on the temperature dependence of the magnetic penetration depth of superconducting Bi2Sr2CaCu2O8+x from measurements of the low-temperature specific heat
Stupp, S. E.; Lee, W. C.; Giapintzakis, John; Ginsberg, D. M. (1992)We have measured the low-temperature (2"10 K) specific heat of polycrystalline Bi2Sr2CaCu2O8+x in zero applied field and in an applied magnetic field of 1 T. We find no field-induced enhancement of the specific heat, to ...
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Article
Development of the optical conductivity with doping in single-domain YBa2Cu3O6+x
Cooper, S. L.; Kotz, A. L.; Karlow, M. A.; Klein, M. V.; Lee, W. C.; Giapintzakis, John; Ginsberg, D. M. (1992)Optical studies of single-domain crystals of YBa2Cu3O6+x allow us to separate the CuO2-plane and CuO-chain contributions to the optical conductivity as a function of doping between 0.025 and 5.5 eV. We find several interesting ...
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Direct measurement of the anisotropy of the resistivity in the a-b plane of twin-free, single-crystal, superconducting YBa2Cu3O7-
Friedmann, T. A.; Rabin, M. W.; Giapintzakis, John; Rice, J. P.; Ginsberg, D. M. (1990)We have measured the resistivity tensor in one nearly twin-free crystal and one twin-free crystal of YBa2Cu3O7-. The first crystal was grown with a large twin-free region. We removed the twins in the second crystal by ...
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Effect of inhomogeneities on the fluctuation-induced cusp in the specific heat of high temperature superconductors
Sharifi, F.; Giapintzakis, John; Ginsberg, D. M.; Harlingen, D. J. Van (1989)We consider the effect of inhomogeneities on the electronic specific heat in high temperature superconductors. We find that a modest spread in the transition temperature of the sample can significantly alter the detailed ...
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Evidence for dx2-y2 pairing from the magnetic field modulation of YBa2Cu3O7-Pb Josephson junctions
Wollman, D. A.; Harlingen, D. J. Van; Giapintzakis, John; Ginsberg, D. M. (1995)We have measured the magnetic field modulation of the critical current of YBCO-Au-Pb Josephson junctions fabricated on the a and b edges and straddling the a-b corners of YBCO single crystals. In corner junctions, the ...
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Article
Evidence of order-parameter symmetry and of a normal metallic state in electron-irradiated YBa2Cu3O7-8 (YBCO)
Ginsberg, D. M.; Giapintzakis, John; Kirk, M. A. (1996)A key difference between a d-wave superconductor and an anisotropic s-wave one is the expected effect of nonmagnetic point defects on Tc. For the former, Tc becomes zero, whereas for the latter, Tc reaches a nonzero constant ...
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Experimental evidence for a multicritical point in the magnetic phase diagram for the mixed state of clean untwinned YBa2Cu3O7
Safar, H.; Gammel, P. L.; Huse, D. A.; Bishop, D. J.; Lee, W. C.; Giapintzakis, John; Ginsberg, D. M. (1993)We report on transport measurements in fields up to 16 T in clean, untwinned single crystals of YBa2Cu3O7 which indicate that there is a critical end point for first-order melting in the H-T phase diagram in the mixed state ...
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Hall effect above Tc in untwinned single-crystal YBa2Cu3O7-x: Normal-state behavior and superconducting fluctuations
Rice, J. P.; Giapintzakis, John; Ginsberg, D. M.; Mochel, J. M. (1991)We present a measurement of the Hall coefficient RH for an untwinned single crystal of YBa2Cu3O7-x. The crystal was produced by a method that does not involve thermomechanical detwinning, and has a resistivity along the ...
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Article
Hall effect in an untwinned single crystal of YBa2Cu3O7-x
Rice, J. P.; Giapintzakis, John; Ginsberg, D. M.; Mochel, J. M. (1991)The Hall coefficient RH for untwinned single-crystal YBa2Cu3O7-x has been measured for the first time. The crystal was produced by a technique not requiring the application of stress. The measurements are made above the ...
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Hall effect in detwinned single crystals of YBa2(Cu1-xZnx)3O7-δ in the mixed state
Schegolev, A. I.; Giapintzakis, John; Manson, J. T.; Ginsberg, D. M.; Dumler, I. (1996)The effect of zinc doping on the mixed-state Hall effect in detwinned single crystals of YBa2Cu3O7-δ has been studied. We observe a sign reveral of the Hall effect in crystals with a superconducting transition temperature ...
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Article
In-plane paraconductivity in a single crystal of superconducting YBa2Cu3O7-x
Friedmann, T. A.; Rice, J. P.; Giapintzakis, John; Ginsberg, D. M. (1989)Resistivity measurements have been made in the a-b plane on a single-crystal sample of superconducting YBa2Cu3O7-x. The resistivity versus temperature curve shows a highly linear region between 150 and 240 K, with an upward ...
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A method for obtaining single domain superconducting YBa2Cu3O7-x single crystals
Giapintzakis, John; Ginsberg, D. M.; Han, P. D. (1989)A method is reported for producing an orthorhombic YBa2Cu3O7-x single crystal comprised entirely of a single untwinned domain. The transformation from a polydomain to a single domain single crystal is carried out by applying ...
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Multiple peaks in the ac susceptibility of untwinned Y-Ba-Cu-O single crystals: A manifestation of the peak effect
Giapintzakis, John; Neiman, R. L.; Ginsberg, D. M.; Kirk, M. A. (1994)We have measured the ac susceptibility of several high quality twinned and detwinned YBa2Cu3O7- (YBCO) single crystals. We see multiple peaks in the (T) curves, and explain them as a manifestation of the peak effect in ...
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Article
Optical studies of the a-, b-, and c-axis charge dynamics in YBa2Cu3O6+x
Cooper, S. L.; Reznik, D.; Kotz, A.; Karlow, M. A.; Liu, R.; Klein, M. V.; Lee, W. C.; Giapintzakis, John; Ginsberg, D. M.; Veal, B. W.; Paulikas, A. P. (1993)Optical and Raman-scattering studies of a-, b-, and c-axis YBa2Cu3O6+x between 0.025 and 5.5 eV are presented as a function of doping, and compared to the results of Bi2Sr2CaCu2O8 and La2-xSrxCuO4. Our doping-dependence ...
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Article
Production and identification of flux-pinning defects by electron irradiation in YBa2Cu3O7-x single crystals
Giapintzakis, John; Lee, W. C.; Rice, J. P.; Ginsberg, D. M.; Robertson, I. M.; Wheeler, R.; Kirk, M. A.; Ruault, M.-O. (1992)An enhancement in Jc of YBa2Cu3O7-x single crystals in a magnetic field is observed after irradiation with 1-MeV electrons. Typically, a factor-of-2 increase in Jc is deduced from magnetic hysteresis loops at 10 K and 1 T ...
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Sign reversal of the Hall effect in YBa2(Cu1-x)3O7-δ single crystals
Neiman, R. L.; Giapintzakis, John; Ginsberg, D. M.; Mochel, J. M. (1995)We have measured the in-plane Hall effect and in-plane resistivity of cobalt-doped YBa2Cu3O7-δ (YBCO) single-crystal samples. The concentration of cobalt ranged from 1 to 3%. As the applied field was varied, a sign reversal ...
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Testing models of the symmetry of the superconducting pairing state by low-temperature electron irradiation of an untwinned single crystal of YBa2Cu3O7-
Giapintzakis, John; Ginsberg, D. M.; Kirk, M. A.; Ockers, S. (1994)We have carried out in situ resistivity measurements in a high-voltage electron microscope to determine how the superconducting transition temperature Tc and the resistivity (T) change with low-temperature electron ...
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Transition temperature and irreversibility line of cobalt-doped single-crystal YBa2Cu3O7-: The effect of high-pressure oxygen annealing
Neiman, R. L.; Giapintzakis, John; Ginsberg, D. M. (1994)We have measured the effect of cobalt on the superconducting transition temperature (Tc) and the dc irreversibility line (IRL) of single-crystal YBa2Cu3O7- (YBCO). Tc of a single crystal annealed in flowing oxygen at ...