Signal sources in AC susceptibility measurements of a granular superconductor

Abstract

This paper examines the sources of signals detected by a mutual inductance bridge in an AC magnetic susceptibility measurement of granular superconductors. Viewing the superconductor as loops of simply connected grains allowed the identification of Meissner currents that produce the in-phase signal and the Faraday induced currents that produce the out-of-phase signals. With this identification it was possible to explain the temperature behavior of the out-of-phase signals.