Defining regions of normal and anomalous skin effect of sintered Bi-based superconductors by the SRPM method

An attempt to develop a method to simultaneously estimate both the resistivity ρ and the magnetic penetration depth λ by vectorially measuring the difference in the impedance between two circular solenoid coils, one with and the other without a cylindrical superconductor, has been made. It was ascertained that the regions of normal and anomalous skin effect can be defined from the frequency dependence of the difference in the impedance between the two coils. The mean free path of electrons l is evaluated by applying the frequency dependence of the difference in the impedance of the coils to the anomalous skin effect region. The values of ρ, λ and l of Bi-based sintered bulks with different J_c were evaluated at liquid N₂ temperature