Title :
Characteristics of YBCO SQUIDs with step-edge and biepitaxial grain boundaries
Author :
Yang, S.Y. ; Chen, C.H. ; Horng, H.E. ; Lee, W.L. ; Yang, H.C.
Author_Institution :
Dept. of Phys, Nat. Taiwan Normal Univ., Taipei, Taiwan
fDate :
6/1/1999 12:00:00 AM
Abstract :
Some characteristics of YBCO SQUIDs with step-edge and biepitaxial grain boundaries were investigated. V-I curves of the step-edge SQUIDs can be described by the RSJ-like model with a linear relationship between the critical current I/sub c/ and temperature T, whereas the typical I/sub c/-T curve for the biepitaxial SQUIDs concaved upward at temperatures near the critical temperature. The V-I curves of both kinds of the step-edge 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 I/sub c/-/spl Phi/ 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.
Keywords :
SQUIDs; barium compounds; grain boundaries; high-temperature superconductors; superconducting epitaxial layers; yttrium compounds; Fraunhofer diffraction; I-V characteristics; RSJ model; Shapiro steps; YBCO SQUID; YBaCuO; biepitaxial grain boundary; critical current; magnetic field modulation; microwave irradiation; step-edge grain boundary; voltage oscillation; Grain boundaries; Magnetic fields; Magnetic modulators; Physics; SQUIDs; Substrates; Superconducting integrated circuits; Temperature; Voltage; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
