Some characteristics of YBCO SQUIDs with stepedge and biepitaxial grain boundaries were investigated. V-I curves of the step-edge SQUIDs can be described by the RSJlikc model with a linear relationship between the critical, current Ic and temperature T, whereas the typical IC-T curve for the biepitaxial SQUIDs concaved upward at temperatures near the critical temperature. The V-I curves of both kinds of the stepedge and the biepitaxial SQUIDs under microwave irradiation revealed integral Shapiro steps. Furthermore, the voltages of the step-edge SQUIDs were well modulated by the applied magnetic field. And also, the typical Fraunhofer diffraction of the lc-t> curve was observed for the single junction in the step-edge SQUIDs. On the other hand, the magnetic field modulated voltage oscillation was also found for the biepitaxial SQUIDs. All the details will be discussed in this report.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering