Inhaltszusammenfassung

A report is presented on the preparation of thin films of the high-Tc superconductor YBa2Cu3O7 by DC-magnetron sputtering and the effects of structural disorder introduced by irradiation with 25 MeV 16O-ions on superconductivity and normal state electrical resistivity. By suitable heat treatments polycrystalline films of different quality could be prepared on SrTiO3 and Al2 O3 substrates. The upper critical field Bc2( T) of high-Tc films measured up to 6 T is linear with dBc2/dT=-2 T/K. Irrad...A report is presented on the preparation of thin films of the high-Tc superconductor YBa2Cu3O7 by DC-magnetron sputtering and the effects of structural disorder introduced by irradiation with 25 MeV 16O-ions on superconductivity and normal state electrical resistivity. By suitable heat treatments polycrystalline films of different quality could be prepared on SrTiO3 and Al2 O3 substrates. The upper critical field Bc2( T) of high-Tc films measured up to 6 T is linear with dBc2/dT=-2 T/K. Irradiation with 25 Me oxygen ions leads to a linear reduction of Tc and an increase of ?(100 K) with fluence. The sensitivity of Tc to irradiation depends significantly on the quality of the films. For high-Tc films B c2(T) remains linear with increasing slope for defect-induced Tc-depressions of about 30 K. As possible mechanisms for the observed Tc-degradation, a defect-induced metal-to-semiconductor transition, which may be caused by a change of the local stoichiometry, and electron localization are discussed. » weiterlesen» einklappen

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Klassifikation

DFG Fachgebiet:
Physik der kondensierten Materie

DDC Sachgruppe:
Physik