Investigation of phasor behavior of high Tc bulk superconductors by AC susceptibility measurements

Abstract

The temperature behavior of a mutual inductance bridge (MIB) was analyzed using phasor diagrams in order to clarify the effect of phase drift caused by the change in resistance of the coils. As a consequence, AC susceptibility measurements of both in-phase and out-of-phase signals tend to include both real and imaginary part of the susceptibility of a sample. It is shown that depending on how phase tuning was performed, one may observe one or two peaks in the out-of-phase measurements. Several solutions to reduce phase drift were also presented.