Title :
Microwave properties of YBCO thin films
Author :
Avenhaus, B. ; Porch, A. ; Lancaster, M.J. ; Hensen, S. ; Lenkens, M. ; Orbach-Werbig, S. ; Muller, E. ; Dahne, U. ; Tellmann, N. ; Klein, N. ; Dubourdieu, C. ; Senateur, J.P. ; Thomas, O. ; Karl, H. ; Stritzker, B. ; Edwards, J.A. ; Humphreys, R.
Author_Institution :
Sch. of Electron. & Electr. Eng., Birmingham Univ., UK
fDate :
6/1/1995 12:00:00 AM
Abstract :
We have measured the microwave properties of high quality YBCO thin films using a copper cavity (87 GHz) and a dielectric resonator (19 GHz) for unpatterned films as well as a coplanar resonator (5, 8, 10, 15 and 16 GHz) for patterned films. For the patterned films the surface resistance (R/sub S/) and non-linear effects were studied as a function of temperature below T/sub C/. For practical applications, the assessment of non-linear effects in the surface resistance are of great importance. The best films showed R/sub S/ approximately constant up to microwave peak current densities of the order of the dc critical current density. The measurements were performed on samples fabricated by a number of different techniques.<>
Keywords :
barium compounds; critical current density (superconductivity); high-temperature superconductors; superconducting critical field; superconducting thin films; surface conductivity; yttrium compounds; 15 to 85 K; 19 GHz; 5 to 16 GHz; 87 GHz; Cu cavity; DC critical current density; DC sputtering; LaAlO/sub 3/; MOCVD; MgO; YBa/sub 2/Cu/sub 3/O/sub 7/; YBaCuO thin films; coplanar resonator; critical fields; dielectric resonator; electron beam coevaporation; laser ablation; microwave peak current densities; microwave properties; nonlinear effects; patterned films; surface resistance; temperature dependence; unpatterned films; Critical current density; Current density; Dielectric measurements; Dielectric thin films; Electrical resistance measurement; Microwave measurements; Surface resistance; Temperature; Transistors; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
