Title :
Properties of lift-off structured high Tc microbridges
Author :
Hauser, B. ; Klopman, B. ; Blank, D. ; Rogalla, H.
Author_Institution :
Div. of Low Temp., Twente Univ., Enschede, Netherlands
fDate :
3/1/1989 12:00:00 AM
Abstract :
Microbridges and DC SQUIDs (superconducting quantum interference devices) were fabricated, using a lift-off technique, from RF sputtered YBaCuO films on MgO single-crystal substrates. Microwave measurements at 9 GHz on microbridges and the magnetic-field dependence of their critical current reveal wide bridge behaviour up to temperatures near the maximum operating temperature of the bridge. Mostly, a linear dependence of the critical current on the temperature is found, which is connected with high intrinsic 1/f noise if the bridge is constant-current-biased slightly above the critical current. In some bridges and DC SQUIDs, regimes with a temperature dependence proportional to (1-T/Tc)1.5 are found. In this case the 1/f noise level is much smaller and SQUID modulation can be followed to about 65 K
Keywords :
SQUIDs; barium compounds; critical currents; electron device noise; high-temperature superconductors; random noise; sputtered coatings; superconducting junction devices; superconducting thin films; yttrium compounds; 1/f noise; 9 GHz; DC SQUIDs; MgO substrate; RF sputtering; SQUID modulation; YBaCuO films; critical current; high temperature superconductor; lift-off technique; magnetic-field dependence; microbridges; microwave measurement; Bridges; Critical current; Radio frequency; Radiofrequency interference; SQUIDs; Superconducting devices; Superconducting films; Superconducting microwave devices; Temperature dependence; Yttrium barium copper oxide;
Journal_Title :
Magnetics, IEEE Transactions on
