engleski

Local field distribution of the vortex lattice near the surface of type-II superconductors - magnetic resonance lineshapes

The magnetic-field distribution of the flux-line lattice near the surface of a superconducting thin film is calculated. The field distribution extends only about d/2 pi outside the superconductor, where d is the intervortex distance, If a spin label of finite thickness is deposited onto the superconductor, its lineshape depends strongly on the penetration depth, label thickness and intrinsic lineshape. The ideal thickness of the surface label ammounts to approximate to d/2 pi. It is shown that a surface ESR experiment is suitable for the determination of the penetration depth lambda in the reversible regime of high-T-c superconductors. In YBa2Cu3O7- delta the obtained slope d lambda(-2)/dT = -1.8 mu m(-2) K-1 just below T-c results in the Ginsburg-Landau parameter kappa approximate to 56.

esr ; flux lattice ; thin films ; London penetration depth ; high-tc superconductors ; nmr decoration technique ; esr-probe decoration

nije evidentirano