Bi2Sr2CaCu2O8+δ single crystals were irradiated with 5.8 GeV Pb-ions to introduce columnar defects (CD). The orientation of the defect structure was altered by changing the direction of incident beam. The peak effect was observed in the sample with CD∥c-axis∥Ba, and it smeared gradually as CD was tilted away from the field direction. The irreversibility field Hirr was scaled with the effective defect density, except for the region where the "recoupling" transition occurs.
ASJC Scopus subject areas