Pairing and coherence transition in La1.82Sr0.18CuO4 strongly two-dimensional superconductor

Abstract

We report conductivity fluctuation measurements in the La 1.82 Sr 0.18 CuO 4 high temperature superconducting material. The conductivity fluctuation analysis was performed by utilizing the concept of the logarithmic derivative of the conductivity excess. Close and above the critical temperature T c , we experimentally determine the occurrence of Gaussian and critical fluctuation regimes. Systematic measurements of conductivity as a function of temperature were performed for several values of transport current j. Fluctuation analysis close to the zero resistivity temperature T c0 was performed and we clearly identified a characteristic exponent, which is analyzed by the dynamical scaling theory and considering a percolation-like transition in a frustrated and disordered system. The observation of a glass-like behavior in our experiments permits to interpret our results as corresponding to a vortex-glass regime.

Conductivity Fluctuation and Some Parameters of High temperature Superconductor Polycrystalline Y1Ba2Cu3O7−δ doped with Silver Nanoparticles

“…According to this table, lower T c values than T LD indicates that the thermodynamically activated Cooper pairs are generated within the grain at comparatively higher temperatures but due to the intragranular disturbances the mean-field critical temperature comes down to lower value. It is possible to infer that the 3D Gaussian regime determines the spatial limit for the obtainment of long-range order of the superconductivity in the material bulk [44]. When the temperature is diminished near T c , first superconductivity is established in the CuO2 planes, as a 2D regime, and crosses up to a well-defined 3D regime [45].…”

Simulación Mediante Dinámica Molecular De Los Cambios Estructurales Durante La Colisión De Nanopartículas De Cobre

“…Dependiendo de la razón entre los tiempos de colisión y coalescencia, los productos finales pueden ser partículas esféricas relativamente grandes o un aglomerado de pequeñas partículas con estructura semejante a la fractal [9]. Diferentes aspectos de los procesos de colisión y coalescencia de clusters tales como la dinámica, cinética, energéticos y térmicos fueron estudiados ampliamente [10][11][12][13][14]. Sin embargo, acerca de los detalles de los cambios estructurales durante la colisión y coalescencia hay poca información.…”