Title :
Directly-coupled DC-SQUID magnetometers made of Bi-Sr-Ca-Cu oxide films
Author :
Matsuda, M. ; Murayama, Y. ; Kiryu, S. ; Kasai, N. ; Kashiwaya, S. ; Koyanagi, M. ; Endo, T. ; Kuriki, S.
Author_Institution :
Electrotech. Lab., Ibaraki, Japan
fDate :
3/1/1991 12:00:00 AM
Abstract :
High-Tc DC-SQUID magnetometers made of Bi-Sr-Ca-Cu oxide films were designed and fabricated. A directly coupled scheme where a SQUID loop and a pick-up loop are connected directly in parallel was chosen to avoid fabricating the multilayered structure. The flux noise, which was measured in FLL (flux locked loop) operation at 4.2 K, increased in a form of 1/f as the frequency decreased below 20 Hz. The level of white noise at the frequency range above 20 Hz was about 1×10-4Φ0/√Hz, corresponding to the field resolution of 1.5 pT/√Hz at the pickup loop
Keywords :
SQUIDs; bismuth compounds; calcium compounds; electron device noise; high-temperature superconductors; magnetometers; strontium compounds; white noise; 1/f; 4.2 K; DC-SQUID magnetometers; FLL; directly coupled scheme; field resolution; flux noise; high-temperature superconductors; pick-up loop; white noise; Bismuth compounds; Circuit noise; Inductance; Magnetic flux; SQUID magnetometers; Sputtering; Superconducting device noise; Superconducting magnets; Temperature dependence; X-ray diffraction;
Journal_Title :
Magnetics, IEEE Transactions on
