Japanese Journal of Applied Physics · 1987 · 30 citations · 9 references
Natural SciencesMaterials SciencePhysicsCondensed Matter PhysicsMagnetic MaterialsSolid State PhysicsMagnetic OxidesMagnetic Properties Of SolidsMagnetic SusceptibilityMagnetism In SolidsStrongly Correlated Electron SystemsSuperconducting MaterialsCritical TemperatureFermi SurfaceHigh-temperature SuperconductivityHigh-temperature SuperconductorsMagnetic Susceptibility MeasurementPenetration DepthSuperconducting PropertiesTemperature Dependence
We have measured the ac magnetic susceptibility of powdered YBa 2 Cu 3 O 7-δ as a function of temperature. The temperature dependence of the London penetration depth estimated from the susceptibility data is quite different from that expected by the BCS theory. The result is well reproduced by the empirical formula λ( T )=λ(0)(1- T / T c ) -1/2 , suggesting the existence of a gapless region on the Fermi surface in the high- T c oxide superconductor.
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NMR of 89Y in normal and superconducting YBa2 Cu3 O9-δ
J. T. Markert, T. W. Noh, Stephen E. Russek et al. · Solid State Communications · 1987 · 126 citations