176,762 research outputs found
Magnetic field dependence of the voltage output of Josephson junctions current-biased on Fiske steps
No full textMicrowave intermodulation study of YBa2Cu3O7-x films in the presence of an external d.c. magnetic field
No full textRole of Cooper Inter-electron interaction with pseudogaps opening in HTS tunneling experiments
No full textUltrathin superconducting Yba2Cu3O7-δ films obtained by high oxygen pressure DC sputterind technique
No full text
Field dependence of the microwave resistivity in SmBa2Cu3O7 thin films
No full textWe report measurements of the microwave complex resistivity at 48 GHz in SmBa2 Cu3 O7−δ thin
films. Measurements are performed with a moderate magnetic field, μ0H < 0.8T, applied along the
c-axis. We find that the complex resistivity presents clear sublinear field dependences, and that the
imaginary part is remarkably sensitive to the moderate magnetic field. Interpretation considering
an unusually strong pinning leads to very anomalous field dependences of the single-vortex viscosity
and of the pinning constant. By contrast, allowing for a significant effect of the magnetic field on
the depletion of the condensate, the data are quantitatively described by the simple free-flow-like
expression, supplemented with two-fluid conductivity. In this frame, we obtain the vortex viscosity
from the data. We compare vortex viscosity in SmBa2Cu3 O7−δ and in YBa 2 Cu3 O7−δ
Metal-insulator transition temperature enhancement in La0.7Ca0.3MnO3 thin films
No full textThe effect of oxygen annealing on the structural and transport properties of La0.7Ca0.3MnO3 thin films deposited on SrTiO3 substrates has been investigated by x-ray diffraction analysis and resistive measurements. The as-grown films are fully tensile strained on the substrates and show a depressed metal-insulator transition temperature T-p= 131 K. As the oxygen content is increased due to longer annealing times, significantly higher T-p are measured, up to 247 K. Correspondingly, an increase of the out-of-plane lattice parameter is observed while the in-plane lattice constants do not change with respect to the as-grown films, which prevents any interpretation of a T-p dependence on the strain. The large increase in T-p is then interpreted in terms of a combined effect of the Mn4+/Mn3+ ratio variation, the change in the carrier density in the a-b planes, and the increase in the hydrostatic strain with the oxygen annealing
- …
