Title :
Surface resistance of YBa2Cu3O7 superconducting films on LaAlO3, NdGaO3 and Al2O3 substrates at varying microwave power levels
Author :
Mazierska, J. ; Grabovickic, R.
Author_Institution :
James Cook Univ. of North Queensland, Townsville, Qld., Australia
Abstract :
Nonlinear performance of High Temperature Superconductors at high RF power levels is still one of major constrains in mass market applications of HTS films in cellular and PCS communication systems. We have measured surface resistance of YBa2Cu3O7 films on several substrates and compared their microwave power-handling capabilities. We have found that for high-quality YBCO films the losses of films on LaAlO3 substrate are the smallest followed by films on NdGaO3 and then on Al2 O3. Also the best quality films exhibited linear behaviour up to very high RF fields. Power-handling properties of YBCO on Al2O3 are improved by very good thermal conduction of sapphire. Best films deposited with the thermal co-evaporation and the off-axis sputtering techniques have been found to be of comparable quality
Keywords :
barium compounds; high-frequency effects; high-temperature superconductors; sputtered coatings; superconducting thin films; surface conductivity; vacuum deposited coatings; yttrium compounds; Al2O3; Al2O3 substrate; LaAlO3; LaAlO3 substrate; NdGaO3; NdGaO3 substrate; RF power level; YBa2Cu3O7; YBa2Cu3O7 superconducting film; high temperature superconductor; loss; microwave power handling; nonlinearity; off-axis sputtering; sapphire; surface resistance; thermal co-evaporation; thermal conduction; Electrical resistance measurement; High temperature superconductors; Microwave measurements; Personal communication networks; Radio frequency; Sputtering; Superconducting films; Surface resistance; Thermal conductivity; Yttrium barium copper oxide;
Conference_Titel :
Microwave Conference, 1999 Asia Pacific
Print_ISBN :
0-7803-5761-2
DOI :
10.1109/APMC.1999.833668
