We report on transient effects in the microwave second-harmonic response of different type of superconductors in the mixed state. The samples have contemporarily been exposed to a dc magnetic field, varying with a constant rate of 60 Oe/s, and a pulsed microwave magnetic field. The time evolution of the signal radiated at the second-harmonic frequency of the driving field has been measured for about 500 s from the instant in which the dc-field sweep has been stopped, with sampling time of ∼0.3 s. We show that the second-harmonic signal exhibits two relaxation regimes; an initial exponential decay, which endures roughly 10 s, and a logarithmic decay in the time scale of minutes. Evidence is given that the decay in the time scale of minutes is ruled by magnetic relaxation over the surface barrier.
|Data di pubblicazione:||2005|
|Titolo:||Surface-barrier effects in the microwave second-harmonic response of superconductors in the mixed state|
|Autori:||AGLIOLO GALLITTO A; GIUNCHI G; LI VIGNI M; VAGLICA G|
|Tipologia:||Articolo su rivista|
|Citazione:||AGLIOLO GALLITTO A, GIUNCHI G, LI VIGNI M, & VAGLICA G (2005). Surface-barrier effects in the microwave second-harmonic response of superconductors in the mixed state. THE EUROPEAN PHYSICAL JOURNAL. B, CONDENSED MATTER PHYSICS, 45, 47-53.|
|Digital Object Identifier (DOI):||10.1140/epjb/e2005-00163-x|
|Appare nelle tipologie:||01 - Articolo su rivista|