Radio frequency response of Ag-sheathed (Bi, Pb)₂Sr₂Ca₂Cu₃O_10+x superconducting tapes

The response of long (Bi,Pb)₂Sr₂Ca₂Cu₃O₁₀ conductors fabricated by the oxide-powder-in-tube method to a radio frequency excitation was investigated while employed as the inductive part of large L-C resonating circuits. After removal of the outer silver sheath, superconducting devices cooled down to 77 K showed superior properties compared to equivalent non-superconducting circuits: Bi-based resonators, conceived for a working frequency in the range between 5 and 17 MHz, presented an improvement of the quality factor by a factor of 20. This result opens new perspectives for the application of Bi-based superconducting materials in the detection of a weak radio frequency signal, as in magnetic resonance imaging.