We report measurements of the electrical and magnetic transport properties of high-quality superconducting Ba1-xKxBiO3 (BKBO) thin films grown by in situ pulsed laser deposition. The best films exhibit sharp resistance and magnetic transitions with zero resistance above 28 K and widths of 0.3 K, and nearly linear normal state resistance extending from the transition to above room temperature. Critical current densities obtained by transport in patterned BKBO lines are greater than 3×106 A/cm2 at 4 K. The transverse magnetoresistance exhibits predominantly BCS-like behavior with an upper critical field slope of -0.78 T/K near T c, giving Hc2(0)=15.2 T and a BCS coherence length =46 Å. We also observe substantial field broadening suggestive of flux flow dissipation.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)