6533b831fe1ef96bd12982c1

RESEARCH PRODUCT

Vortex-system ordering during magnetisation measurements in YBa2Cu3O7−δ films at low temperatures

Gerhard JakobH. AdrianDana MiuL. Miu

subject

SuperconductivityMaterials scienceCondensed matter physicsRelaxation (NMR)DopingEnergy Engineering and Power TechnologyActivation energyCondensed Matter PhysicsElectronic Optical and Magnetic MaterialsMagnetic fieldVortexMagnetizationCondensed Matter::SuperconductivityElectrical and Electronic EngineeringScaling

description

Abstract Zero-field-cooling dc magnetisation relaxation measurements performed on optimally doped epitaxial YBa 2 Cu 3 O 7− δ films with the external magnetic field H oriented parallel to the c -axis reveal the ordering of the creeping vortex-system in the low temperature T domain, due to the macroscopic currents induced in the sample. This dynamic ordering manifests itself through the appearance of a maximum in the T variation of the normalised vortex-creep activation energy. The location of this maximum in the H – T plane describes a well-defined current induced order–disorder line. Our results suggest the absence of a static elastic vortex glass in disordered high-temperature superconductors at high H , and the current induced ordering of the vortex-system as a possible origin for the current–voltage characteristic scaling in terms of an elastic vortex glass–vortex liquid transition.

https://doi.org/10.1016/j.physc.2007.04.050