Current voltage characteristics of Bi2Sr2Ca1Cu2O8 single crystals - possible plastic deformations of the vortex lattice

Abstract The J-E curves (JEC) for Bi 2+x Sr 2+y Ca 1+z Cu 2 O 8+t single crystals have been extracted from the results of VSM magnetic measurements. The obtained data show the existence of two temperature regions with a transition temperature T ∗ between 15 and 20 K being dependent on the voltage criteria. Below T ∗ , JECs are described quite well by a power-like law E/E c = ( J/ J c ) n with n∝1/T. For high magnetic fields it is found that 1/n ∝B. A model considering the “pancake” vortex-antivortex pair excitation provides good consistency with the experimental data.