Applied Physics Letters · 1990 · 87 citations · 6 references
Natural SciencesMaterials SciencePhysicsCondensed Matter PhysicsMaterials PhysicsThin FilmsElectrical ConductivityElectrical Properties Of CeramicsMicrowave MaterialsSuperconducting Thin FilmsTerahertz SpectroscopyThin Film Electrical PropertiesCharacterization Of Microwave MaterialsConductivityCritical Current DensityCurrent DensityEpitaxial Thin FilmsHigh-frequency ElectronicsSurface ResistanceTemperature Dependence Of Electrical Properties
We report measurements of the dc and microwave properties of epitaxial thin films of Tl2CaBa2Cu2O8 on LaAlO3. ac magnetic susceptibility measurements yield critical temperatures at the transition midpoint Tc∼100 K and 10–90% transition widths of ∼1.0 K. We observed a critical current density of 1.06×106 A/cm2 at 77 K measured by dc transport. We measured a low-power surface resistance of Rs=0.2 mΩ at 9.55 GHz and 77 K. This is ∼50 times lower than oxygen-free high-conductivity (OFHC) Cu at the same frequency and temperature. At 90 K, RS rises to 0.4 mΩ, and at 95 K, RS=0.7 mΩ. We measured the microwave power dependence of RS at 77, 90, and 95 K. At high microwave field (≳30 G, 77 K) Rs=0.8 mΩ, more than ten times lower than OFHC Cu.
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Low-loss microstrip delay line in Tl2Ba2CaCu2O8
L. C. Bourne, R. B. Hammond, McD. Robinson et al. · Applied Physics Letters · 1990 · 52 citations