DocumentCode :
857996
Title :
Large area YBa/sub 2/Cu/sub 3/O/sub 7/ films for high power microwave applications
Author :
Face, D.W. ; Wilker, C. ; Zhi-Yuan Shen ; Pang, P. ; Small, R.J.
Author_Institution :
DuPont Central Res. & Dev.., Wilmington, DE, USA
Volume :
5
Issue :
2
fYear :
1995
fDate :
6/1/1995 12:00:00 AM
Firstpage :
1581
Lastpage :
1586
Abstract :
We have developed large area YBa/sub 2/Cu/sub 3/O/sub 7/ films (/spl ges/2 inch diameter) which have low microwave surface resistance at high microwave power levels. The films are produced by off-axis sputtering using a noncontact direct radiant heating technique. Thickness and composition are uniform to within /spl plusmn/3% and T/sub c/ is uniform to within /spl plusmn/1 K across 3 inch diameter wafers. The microwave surface resistance of these films has been measured over a wide range of temperature (20 K to 80 K) and microwave power. At 20 K, the surface resistance remains below 100 /spl mu//spl Omega/ (at 10 GHz) for microwave surface current densities up to 4.6/spl times/10/sup 6/ A/cm/sup 2/. At 70 K, the surface resistance remains below 350 /spl mu//spl Omega/ (@ 10 GHz) for microwave curent densities up to 1.3/spl times/10/sup 6/ A/cm/sup 2/. High power microwave transmission lines (14 /spl mu/m produced with these films are capable of transmitting microwave power up to +25 dBm (>2.3/spl times/10/sup 6/ A/cm/sup 2/ average current density) at 70 K.<>
Keywords :
barium compounds; high-frequency effects; high-frequency transmission lines; high-temperature superconductors; power transmission lines; sputter deposition; superconducting thin films; superconducting transition temperature; surface conductivity; yttrium compounds; 10 GHz; 100 muohm; 14 mum; 20 to 80 K; 3 in; 350 muohm; 70 K; YBa/sub 2/Cu/sub 3/O/sub 7/; high microwave power levels; high power microwave applications; high power microwave transmission lines; high temperature superconductors; large area YBa/sub 2/Cu/sub 3/O/sub 7/ films; low microwave surface resistance; microwave surface current densities; noncontact direct radiant heating; off-axis sputtering; superconducting transition temperature; Electrical resistance measurement; Electromagnetic heating; Geometry; Microwave measurements; Power measurement; Sputtering; Substrates; Superconducting films; Surface resistance; Temperature;
fLanguage :
English
Journal_Title :
Applied Superconductivity, IEEE Transactions on
Publisher :
ieee
ISSN :
1051-8223
Type :
jour
DOI :
10.1109/77.402875
Filename :
402875
Link To Document :
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