Inhaltszusammenfassung

Using heavy-ion irradiation, we produced columnar defects of different density and orientation in epitaxial Bi2Sr2CaCu2O8 thin films. Although this increases the normal state resistivity and the critical temperature is reduced proportionally to the volume fraction of damaged material, pinning-related quantities like critical current density, activation energy and depinning field are enhanced in external magnetic fields. Transport measurements in dependence of the magnetic field and its orient...Using heavy-ion irradiation, we produced columnar defects of different density and orientation in epitaxial Bi2Sr2CaCu2O8 thin films. Although this increases the normal state resistivity and the critical temperature is reduced proportionally to the volume fraction of damaged material, pinning-related quantities like critical current density, activation energy and depinning field are enhanced in external magnetic fields. Transport measurements in dependence of the magnetic field and its orientation consistently indicate two-dimensional pinning of pancake vortices at the columnar defects. We observe the absence of correlated flux pinning by columnar defects and compare to heavy-ion-irradiated single crystals and tapes, where line-like correlations have been observed. » weiterlesen» einklappen

Autoren

Klassifikation

DFG Fachgebiet:
Physik der kondensierten Materie

DDC Sachgruppe:
Physik