Flux creep, shielding current and irreversibility field in Kr irradiated Bi 2Sr 2CaCu 2O x single crystals
The influence of high energy Kr irradiation on the shielding current, irreversibility field and flux creep rate in Bi 2Sr 2CaCu 2O x single crystals has been studied. For B « BΨ = φ 0·Ψ the pinning and creep behavior is approximately independent of fluence but significantly different from the virgin state. For high magnetic fields three temperature regions were distinguished. Small changes of the irreversibility field spite of a large increase of the shielding current with fluence point that plastic deformations dominate in the low temperature regime. The high T region is determined by the single vortex-single track interaction, whereas at intermediate temperatures the pinning of several vortices by one track becomes important.