Title :
Direct-coupled high T/sub c/ DC SQUID gradiometer with single layer YBa/sub 2/Cu/sub 3/O/sub 7/
Author :
Yunsung Huh ; Soon-Gul Lee ; In-Seon Kim ; Yong Ho Lee ; Hyuk Chan Kwon ; Yong Ki Park ; Jong-Chul Park ; Insang Song ; Gwangseo Park
Author_Institution :
Dept. of Phys., Sogang Univ., Seoul, South Korea
fDate :
6/1/1997 12:00:00 AM
Abstract :
We have studied first derivative high T/sub c/ dc SQUID (Superconducting QUantum Interference Device) gradiometer from a single layer of Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7/ thin film using pulsed laser deposition (PLD) and argon ion beam etching method. The planar gradiometer consists of two pickup loops coupled directly to dc SQUID with an inductance of about 20 pH in the center of the structure. The gradiometer contains step-edge type junctions of 3 /spl mu/m width and is made on the SrTiO/sub 3/ substrate of 12/spl times/25 mm/sup 2/ in size. The SQUID showed RSJ type junction I-V characteristics with T/sub c/ of 86 K and swing voltage of /spl sim/4 /spl mu/V at 79.3 K. The magnetometer was sensitive only to the gradient of the magnetic field with well balanced null response to uniform fields.
Keywords :
SQUID magnetometers; barium compounds; high-temperature superconductors; superconducting thin films; yttrium compounds; 4 muV; 79.3 K; I-V characteristics; RSJ junction; SrTiO/sub 3/ substrate; YBa/sub 2/Cu/sub 3/O/sub 7/; YBa/sub 2/Cu/sub 3/O/sub 7/ thin film; argon ion beam etching; critical temperature; direct-coupled high T/sub c/ DC SQUID gradiometer; inductance; magnetometer; pickup loop; planar gradiometer; pulsed laser deposition; single layer; step-edge junction; swing voltage; Argon; Interference; Optical pulses; Pulsed laser deposition; SQUIDs; Sputtering; Superconducting devices; Superconducting epitaxial layers; Superconducting thin films; Thin film devices;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
