Voltage Response of AC Susceptibility and Pinning Effects in Hg0.69Pb0.31Ba2Ca2Cu3O8+δ

Abstract

We have studied the voltage response of AC susceptibility,and from the imaginary part of the susceptibility experimental results a new method is presented in terms of the material equation to investigate the pinning properties and the dynamical response in our Hg _0.69 Pb _0.31 Ba ₂ Ca ₂ Cu ₃ O _8+δ sample. We also discuss the differences between the voltage criterion and our AC response measurement method in order to determine the value of the true critical current density. The result shows that the later method reflects the true critical state of high-temperature superconductivity better than the general voltage criterion.