Title :
High-T/sub c/ superconducting EuBa/sub 2/Cu/sub 3/O/sub y/ thin films and MgO and YAlO/sub 3/ for coplanar devices
Author :
Asano, H. ; Satoh, M. ; Konaka, T.
Author_Institution :
NTT Lab., Ibaraki, Japan
fDate :
3/1/1993 12:00:00 AM
Abstract :
The authors have studied the microwave properties of high-T/sub c/ superconducting EuBa/sub 2/Cu/sub 3/O/sub y/ (EBCO) films on MgO and YAlO/sub 3/ substrates with low dielectric constants ( in =10 and 16, respectively), and a low loss tangent (tan delta <10/sup -5/). Measurements of surface resistance R/sub s/ at 50 GHz in a cavity show that EBCO films exhibit low R/sub s/ values (77 K) of 2-10 m Omega . A microstructural study using transmission electron microscopy showed that crystal defects related to the in-plane misorientation are observed for films with higher R/sub s/ values. The R/sub s/ values of the patterned films were measured in a coplanar transmission line resonator. A typical value for patterned films was 28 mu Omega at 4 GHz and 28 K.<>
Keywords :
barium compounds; cavity resonators; europium compounds; high-temperature superconductors; superconducting microwave devices; superconducting thin films; 2 to 10 mohm; 28 K; 28 muohm; 4 GHz; 50 GHz; EuBa/sub 2/Cu/sub 3/O/sub y/ thin films; MgO substrates; YAlO/sub 3/ substrates; coplanar devices; coplanar transmission line resonator; crystal defects; high-T/sub c/ superconducting; in-plane misorientation; low loss substrates; low permittivity substrates; microstructural study; microwave properties; patterned films; surface resistance; transmission electron microscopy; Dielectric constant; Dielectric losses; Dielectric measurements; Dielectric substrates; Electrical resistance measurement; Electrons; Superconducting films; Superconducting microwave devices; Superconducting transmission lines; Surface resistance;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
