Title :
Noise properties of YBa2Cu3O7-x step-edge junction dc SQUID magnetometers prepared on sapphire substrates
Author :
Lim, Hae-Ryong ; Kim, In-Seon ; Park, Yong Ki ; Kim, Dong Ho
Author_Institution :
Korea Res. Inst. of Standard Sci., Taejon, South Korea
fDate :
3/1/2001 12:00:00 AM
Abstract :
Step-edge YBa2Cu3O7-x (YBCO) dc SQUID magnetometers on sapphire substrates have been fabricated. CeO2 buffer layers and YBCO films were deposited in situ on the low angle (~35°) steps formed on the sapphire substrates with various thickness ratio of YBCO thin film to step height. Noise properties of the magnetometer exhibit quite different behavior according to the thickness ratio. The field noise of the dc SQUID magnetometer was measured to be 100~300 fT/√Hz at 100 Hz and about 1.5 pT/√Hz at 1 Hz with a dc bias method, and 450 fT/√Hz at 1 Hz with an ac bias method
Keywords :
SQUID magnetometers; barium compounds; high-temperature superconductors; pulsed laser deposition; superconducting device noise; superconducting thin films; yttrium compounds; 1 Hz; 100 Hz; Al2O3; CeO2; CeO2 buffer layers; YBa2Cu3O7-x step-edge junction dc SQUID magnetometers; YBa2Cu3O7; ac bias method; dc bias method; field noise; film thickness ratio; in situ deposition; low angle steps; noise properties; pulsed laser deposition; sapphire substrates; step height; Buffer layers; Fabrication; Gold; Josephson junctions; Magnetic properties; Milling; SQUID magnetometers; Substrates; Transistors; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
