Title :
Tl/sub 2/Ba/sub 2/CaCu/sub 2/O/sub 8/ films: Growth and applications in dc SQUIDs and microwave devices
Author :
Chen, Y.F. ; Ivanov, Z.G. ; Johansson, L.-G. ; Kojouharov, R.I. ; Angelov, I.M. ; Olsson, E. ; Roddatis, V.A. ; Stepantsov, E.A. ; Tzalenchuk, A.Y. ; Vasiliev, A.L. ; Claeson, T.
Author_Institution :
Chalmers Univ. of Technol., Goteborg, Sweden
fDate :
6/1/1997 12:00:00 AM
Abstract :
Tl-2212 thin films were grown ex situ in a two step process on a variety of substrates, including ones with artificially introduced high angle steps. Grain boundary weak links were formed on LaAlO/sub 3/ substrates with steps and on bicrystal substrates and were employed in dc SQUIDs. The white noise level of the SQUIDs was 50/spl mu//spl Phi//sub 0///spl radic/(Hz) at 77 K. A 12.5 GHz HEMT oscillator stabilized with a Tl-2212 resonator gave 8-10 dB lower phase noise than using a gold resonator.
Keywords :
1/f noise; Josephson effect; SQUIDs; barium compounds; calcium compounds; high-temperature superconductors; phase noise; superconducting device noise; superconducting device testing; superconducting epitaxial layers; superconducting microwave devices; superconducting resonators; superconducting thin films; thallium compounds; white noise; 1/f noise; 12.5 GHz; 77 K; HEMT oscillator stabilization; LaAlO/sub 3/; LaAlO/sub 3/ substrates; Tl-2212 resonator; Tl/sub 2/Ba/sub 2/CaCu/sub 2/O/sub 8/; Tl/sub 2/Ba/sub 2/CaCu/sub 2/O/sub 8/ films; artificially introduced high angle steps; bicrystal substrates; dc SQUIDs; epitaxial c-axis orientation; ex situ growth; grain boundary weak links; microwave devices; phase noise; two step process; white noise level; Bridge circuits; Critical current; Grain boundaries; Microwave devices; Noise level; Noise measurement; SQUIDs; Temperature dependence; Voltage; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
