The influence of slow cooling on Y211 size and content in single-grain YBCO bulk superconductor through the infiltration-growth process

International audienceHighly textured YBa2Cu3O7-(delta) (Y123) superconductors were produced using modified Textured Top Seeded Infiltration Growth (TSIG) process. The liquid source is made of only Y123 powder whereas the solid source is composed of Y2BaCuO5 (Y211) powder. We aim to control the amount of liquid that infiltrates the solid pellet, which in turn controls the final amount of Y2BaCuO5 particles in Y123 matrix. The effect of the slow cooling kinetics on sample morphology, on grain growth and on final microstructure was too investigated. It is shown that appropriate slow cooling time may also contribute to the control of the amount of Y211 inclusions in the final structure of Y123 bulk. We report herein the Y211 particle size and density distribution in the whole Y123 matrix. The present work proves that finest Y211 particles locate under the seed and that their size and density increase with distance from the seed

The influence of slow cooling on Y211 size and content in single-grain YBCO bulk superconductor through the infiltration-growth process

International audiencez Highly textured YBa2Cu3O7-(delta) (Y123) superconductors were produced using modified Textured Top Seeded Infiltration Growth (TSIG) process. The liquid source is made of only Y123 powder whereas the solid source is composed of Y2BaCuO5 (Y211) powder. We aim to control the amount of liquid that infiltrates the solid pellet, which in turn controls the final amount of Y2BaCuO5 particles in Y123 matrix. The effect of the slow cooling kinetics on sample morphology, on grain growth and on final microstructure was too investigated. It is shown that appropriate slow cooling time may also contribute to the control of the amount of Y211 inclusions in the final structure of Y123 bulk. We report herein the Y211 particle size and density distribution in the whole Y123 matrix. The present work proves that finest Y211 particles locate under the seed and that their size and density increase with distance from the seed. (C) 2017 Elsevier B.V. All rights reserved

Vortex pinning properties of –Ba–Cu–O and –Ba–Cu–O superconducting bulks

International audienceCrystalline defects on the nano-scale were successfully introduced into YBCO high-temperature superconductors (HTS) by ZrO2 nanometer particles addition in order to strongly pin the quantized vortices. Three batches of ZrO2 nano-particles with different particle size distributions were used. The corresponding mean nano-particle diameters are respectively, 287, 536 and 764 nm. Serving as artificial pinning centers (APC), non-superconducting nano-particles cause a remarkable enhancement of critical current density (Jc) at T = 77 K. This improvement has been shown to depend on the size of APC. The pinning strength of nano-particles inclusions has been found to be greater with wide size dispersed nano-particles. Our results indicate that pinning properties and vortex dynamics depend on the size of APCs. The introduction of APCs with controlled size is indispensable to achieve a high Jc