Transport measurements on Bi_2Sr_2CaCu_2O(8+ delta ) single crystals with columanar defects

摘要

Out-of-plane and flux transformer geometry transport measurements have been made on Bi_2Sr_2CaCu_2O(8+ delta ) single crystals containing columnar defects introduced by heavy ion irradiation. Resistive transitions are used to extract the critical exponents of the Boseglass phase. The in-plane and out-of-plane exponents are consistent with recent predictions~1 for applied fields smaller than the matching field B_( PHI). The experimental results also show remarkable agreement with the phase diagram predicted by Nelson and Vinokur~2 to distinguish the vortex-glass and Bose-glass phases.