Electromagnetic properties and He+ irradiation effects on YBa2Cu3O7-x grain-boundary Josephson junctions

Article

关键词: ELECTRON-BEAM IRRADIATION;    REDUCED CRITICAL CURRENTS;    THIN-FILMS;    TRANSPORT-PROPERTIES;    BICRYSTALS;    SUPERCONDUCTORS;    MISORIENTATION;    RESONANCES;    SCALE;   

DOI  :  10.1103/PhysRevB.61.6422

来源: SCIE

【 摘 要 】

We have analyzed the electromagnetic properties of small and long YBa2Cu3O7-x grain-boundary Josephson junctions. The Swihart velocity increases with junction width (rv) while the ratio of the relative dielectric constant to the barrier thickness (epsilon/t) decreases. We found that the product wX epsilon/t is approximately constant. These results have been explained in the framework of the filamentary model, where the barrier can be regarded as a disordered dielectric medium with a high density of superconducting filaments. Experiments demonstrate that a controllable variation of these parameters can be achieved by helium irradiation at 80 keV. We give examples of an enhancement of weak-link properties of junctions for doses in the range of 10(13) cm(-2) Raising the dose we can sweep the modification of the weak-link properties from an increase of the junction critical current of about 10% to a severe degradation of the coupling energy of the barrier, although the superconducting properties of the electrodes always worsen gradually.

【 授权许可】

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