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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-
(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 ...
Optical studies of the a-, b-, and c-axis charge dynamics in YBa2Cu3O6+x
(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 ...
Production and identification of flux-pinning defects by electron irradiation in YBa2Cu3O7-x single crystals
(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 ...
Direct measurement of the anisotropy of the resistivity in the a-b plane of twin-free, single-crystal, superconducting YBa2Cu3O7-
(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 ...
In-plane paraconductivity in a single crystal of superconducting YBa2Cu3O7-x
(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 ...
Vortex-motion-induced voltage noise in YBa2Cu3O7- single crystals
(1995)
We have investigated vortex motion below the quasistatic melting transition in a detwinned YBa2Cu3O7- single crystal by measuring the differential resistance and the voltage noise. With the magnetic field parallel to the ...
Transition temperature and irreversibility line of cobalt-doped single-crystal YBa2Cu3O7-: The effect of high-pressure oxygen annealing
(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 ...
Tunneling in Pb-YBCO junctions: Determining the symmetry of the pairing state
(1995)
We report on our efforts to understand the origin of supercurrent observed in c-axis tunnel junctions on YBCO [Sun A. G. et al., Phys. Rev. Lett. 72, 2267 (1994).] by studying the phase coherence of a-axis/c-axis and ...
Anisotropy of the optical dielectric function in the ab plane for YBa2Cu3O7-
(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 ...
Hall effect in detwinned single crystals of YBa2(Cu1-xZnx)3O7-δ in the mixed state
(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 ...