Inhaltszusammenfassung

The dependence of resistive transitions, thermal activation energies, and critical current densities of YBa2(Cu1-x Znx)xO7-? and YBa2 (Cu1-xNix)3O7-x- thin films on B, T, and the angle ? between the magnetic field and the c-axis is studied. A decrease of the critical temperature Tc with increasing doping concentration x is observed. For small x an increase of the activation energy is found, with a maximum around 0.2%. This can be explained by a model assuming local pinning potentials due to t...The dependence of resistive transitions, thermal activation energies, and critical current densities of YBa2(Cu1-x Znx)xO7-? and YBa2 (Cu1-xNix)3O7-x- thin films on B, T, and the angle ? between the magnetic field and the c-axis is studied. A decrease of the critical temperature Tc with increasing doping concentration x is observed. For small x an increase of the activation energy is found, with a maximum around 0.2%. This can be explained by a model assuming local pinning potentials due to the impurity atoms, which begin to overlap for higher concentrations. The films exhibit higher jc values for small dopant concentrations than without doping. If the angle ? is changed, a different j c(B, T, ?) behavior is found than in high-quality undoped films, with additional structures in the curves. » weiterlesen» einklappen

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Klassifikation

DFG Fachgebiet:
Physik der kondensierten Materie

DDC Sachgruppe:
Physik