Critical current density versus normal-state resistivity in granular high-temperature superconductors with different average grain size
S R Currás; J A Veira; J Maza; Félix Vidal; S R Currás; Laboratorio de Bajas Temperaturas y Superconductividad<sup>1</sup>, Departamento de Física de la Materia Condensada, Universidad de Santiago de Compostela, E15706, Spain; J A Veira; Laboratorio de Bajas Temperaturas y Superconductividad<sup>1</sup>, Departamento de Física de la Materia Condensada, Universidad de Santiago de Compostela, E15706, Spain; J Maza; Laboratorio de Bajas Temperaturas y Superconductividad<sup>1</sup>, Departamento de Física de la Materia Condensada, Universidad de Santiago de Compostela, E15706, Spain; Félix Vidal; Laboratorio de Bajas Temperaturas y Superconductividad<sup>1</sup>, Departamento de Física de la Materia Condensada, Universidad de Santiago de Compostela, E15706, Spain
Журнал:
Superconductor Science and Technology
Дата:
2000-07-01
Аннотация:
The resistivity, ρ, and the critical current density at zero applied magnetic field, J<sub>c</sub>, of ceramic Y<sub>1</sub>Ba<sub>2</sub>Cu<sub>3</sub>O<sub>7-δ</sub> samples with different average grain size, a (from 5 to 14 µm), are reported. These results show that at a given temperature J<sub>c</sub> depends only on the specific contact resistance of the average grain boundary junction, ρ<sub>□</sub>, so that the product J<sub>c</sub>ρ<sub>□</sub> is sample independent. The relevance of ρ<sub>□</sub> and not of a on J<sub>c</sub> has been further tested on a subset of samples having very different average grain size but similar ρ<sub>□</sub> for which negligible variations of J<sub>c</sub> are observed.
183.9Кб