A novel high-Tc superconducting (HTS) buffered step-edge Josephson junction is fabricated. A 250nm PrBa2Cu3O 7 (PBCO) layer was epitaxially grown on a (001) MgO substrate by PLD, which acts as a buffered template for a step-edge. Argon-ion milling was used to obtain a step-edge with a step angle of 25°. The step-edge is analysed in terms of an extended Wu and Chen model (Wu and Chen 2006 Rev. Sci. Instrum. 77 1). The model validity is confirmed by the correspondence between the theoretically proposed and experimentally observed step angles. A 150nm YBa 2Cu3O7-δ (YBCO) thin film was accordingly grown over the PBCO step-edge and patterned by standard photolithography. I-V characteristics were obtained by DC and AC excitation of the patterned junctions. The IcRn product values are of the order of 1.6mV and 0.36mV at 53K and 77K, respectively. These values are higher than typical values found in the literature. The observation of Shapiro steps confirms the presence of the Josephson effect in this novel junction topology.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials