Magnetic Investigations of Hg-based HTSC: Evidence for Different Kinds of Pinning

摘要

For different Hg-based superconducting ceramics (Hg-1223 and (Hg, Pb)-1223), the irreversibility lines were determined by means of ac and dc magnetization measurements. In the case where the peak values of the imaginary parts of the ac susceptibility are used under certain conditions a double peak structure occurs in these parts, affecting the irreversibility line. It seems that this result is evident for different kinds of pinning, occurring in two phases with different superconducting properties.