Inhaltszusammenfassung

The resistive transitions to superconductivity were investigated in a series of c-axis oriented (YBa2Cu3O7)nY/ (PrBa2Cu3O7)nPr-superlattices with one unit cell thick YBa2Cu3O7 sheets (nY = 1) and varying thickness of the decoupling PrBa2Cu3O7 sheets (18 ? nPr ? 1). These samples were prepared by alternating dc-sputtering from stoichiometric YBa2Cu3O7 and PrBa2Cu3O7 targets. The resistive transitions to superconductivity are broadened due to the thermal excitation of vortex-antivortex-pairs an...The resistive transitions to superconductivity were investigated in a series of c-axis oriented (YBa2Cu3O7)nY/ (PrBa2Cu3O7)nPr-superlattices with one unit cell thick YBa2Cu3O7 sheets (nY = 1) and varying thickness of the decoupling PrBa2Cu3O7 sheets (18 ? nPr ? 1). These samples were prepared by alternating dc-sputtering from stoichiometric YBa2Cu3O7 and PrBa2Cu3O7 targets. The resistive transitions to superconductivity are broadened due to the thermal excitation of vortex-antivortex-pairs and a scaling of the resistivity to a Kosterlitz Thouless behavior is possible. From this scaling we determined the mean field Tc and the Kosterlitz Thouless temperature TKT. A systematic increase of the Kosterlitz Thouless parameter ?KT = (Tc ? TKT)/Tc from 0.12 for nPr = 1 to 0.82 for nPr = 18 with increasing decoupling was found. » weiterlesen» einklappen

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DFG Fachgebiet:
Astrophysik und Astronomie

DDC Sachgruppe:
Physik