Structural and Fluctuation Induced Excess Conductivity in R:1113 Superconductors



Título del documento: Structural and Fluctuation Induced Excess Conductivity in R:1113 Superconductors
Revista: Brazilian journal of physics
Base de datos: PERIÓDICA
Número de sistema: 000392504
ISSN: 0103-9733
Autores: 1
2
Instituciones: 1Assiut University, Faculty of Science, Assiut. Egipto
2Damietta University, Faculty of Science at New Damietta, New Damietta. Egipto
Año:
Periodo: Abr
Volumen: 46
Número: 2
Paginación: 198-205
País: Brasil
Idioma: Inglés
Tipo de documento: Artículo
Enfoque: Experimental, analítico
Resumen en inglés We report here the fluctuation-induced excess conductivity in RBaSrCu3O7-δ (R = Y, Gd, Nd, and La) superconductor. It is found that Y and Gd samples are orthorhombic, while the Nd and La samples are quasi-tetragonal. The oxygen content is found to be close to 7 for all R:1113 samples. The logarithmic plots of Δσ and reduced temperature Є reveal two different exponents corresponding to crossover temperature due to shifting the order parameter from (2D/1D) to (3D). The critical temperature, mean field temperature, crossover temperature, out of plane coherence length, and interlayer coupling are decreased as the ionic size increases. While the in plane and effective coherence lengths, and anisotropy are increased. We have also estimated several physical parameters such as upper critical magnetic fields in both a-b- and c-axis (Bab and BC), and critical current density J (0 K), and their values are found to be decrease as the ionic size increases. The results are discussed in terms of oxygen rearrangement, localization of carriers, coherence lengths, and anisotropy which are produced as the ionic size increases
Disciplinas: Física y astronomía
Palabras clave: Física de materia condensada,
Superconductores,
Cerámica,
Síntesis química,
Difracción de rayos X,
Propiedades eléctricas,
Propiedades de transporte
Keyword: Physics and astronomy,
Condensed matter physics,
Superconductors,
Ceramics,
Chemical synthesis,
X-ray diffraction,
Electrical properties,
Transport properties
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