Peak effect and Bose-glass transition of the heavy-ion irradiated Bi2212: Effect of the defect configuration

Bi2Sr2CaCu2O8+delta single crystals were irradiated with 5.8 GeV Pb-ions to introduce columnar defects (CD). The orientation of the defect structure w as altered by changing the direction of incident beam. The peak effect was observed in the sample with CD parallel to c-axis parallel to B-a, and it s meared gradually as CD was tilted away from the field direction. The irreve rsibility field Wi,, was scaled with the effective defect density, except f or the region where the "recoupling" transition occurs. (C) 2000 Elsevier S cience B.V. All rights reserved.