Coherence lengths and anisotropy in MgB2 superconductor

Abstract

Field and temperature microwave measurements have been carried out on MgB2 thin film grown on Al2O3 substrate. The analysis reveals the mean field coherence length xi_{MF} in the mixed state and a temperature independent anisotropy ratio gamma_{MF} = xi_{MF}^{ab} / xi_{MF}^c approximately 2. At the superconducting transition, the scaling of the fluctuation conductivity yields the Ginzburg-Landau coherence length with a different anisotropy ratio gamma_{GL} = 2.8, also temperature independent.

submitted to PRL

References in corpus (13)

• MgB2 superconducting thin films with a transition temperature of 39 Kelvin
• Temperature and field dependence of the anisotropy of MgB2
• High current-carrying capability in c-axis-oriented superconducting MgB2 thin films
• Anisotropy of the Upper Critical Field and Critical Current in Single Crystal MgB${}_2$
• Multiband model for penetration depth in MgB2
• Mixed state properties of superconducting MgB2 single crystals
• Superconducting properties of well-shaped MgB2 single crystal
• Temperature dependence and anisotropy of the bulk upper critical field H_c2 of MgB_2
• Energy gap, penetration depth and surface resistance of MgB2 thin films determined by microwave resonator mesurements
• Reflection of two-gap nature in penetration depth measurements of MgB${}_2$ film
• Superconducting anisotropy and evidence for intrinsic pinning in single crystalline MgB${}_2$
• Anisotropy in c-oriented MgB2 thin films grown by Pulsed Laser Deposition
• Angular dependence of magnetoresistivity in c-oriented MgB2 thin film

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• Superconducting fluctuations in FeSe${}_{0.5}$Te${}_{0.5}$ thin films probed via microwave spectroscopy
• Modes of an elliptical cylindrical resonant cavity -- analytical solution
• Uranium Doping and Thermal Neutron Irradiation Flux Pinning Effects in MgB2