Reinterpretation of AC susceptibility features of YBCO in a mutual inductance bridge based on phase de-tuning

Abstract

AC magnetic susceptibility of YBCO was performed in a basic mutual inductance bridge at various frequencies and applied magnetic fields. Careful analysis of the behavior of the in-phase and out-of-phase signals confirmed that the broadening in the in-phase trace reflects a projection of the AC loss signal that shows as a peak in the out-of-phase measurements. Since the MIB uses no external corrective circuitry, the projection of the out-of-phase signal onto the in-phase is attributed to phase de-tuning. Hence, there is no need to formulate exotic mechanisms to explain this phenomena.