In this work, we report on directionally solidified YBCO bars fabricated by the horizontal Bridgman technique based on sample transport in a thermal gradient. We employ a pulling rate in the furnace three orders of magnitude higher than the value of 0.5 mm/h generally used to maximize the critical current densities. We cut the produced sample in several slices perpendicularly to the pulling direction with the purpose of analysing the spatial distribution of superconducting, morphological and structural properties as a function of their position along the pulling direction. X-ray diffraction and SEM analyses show that partial texturing occurs even at very high pulling rates. Each slice has an onset of the critical temperature at /spl sim/90 K Moreover, the critical current densities at 77 K and at 1 Tesla are estimated from dc magnetisation curves in hundreds of A/cm/sup 2/.
Spatial distribution of Structural and superconducting properties in high processing rate melt textured YBCO
AVecchione;
1999
Abstract
In this work, we report on directionally solidified YBCO bars fabricated by the horizontal Bridgman technique based on sample transport in a thermal gradient. We employ a pulling rate in the furnace three orders of magnitude higher than the value of 0.5 mm/h generally used to maximize the critical current densities. We cut the produced sample in several slices perpendicularly to the pulling direction with the purpose of analysing the spatial distribution of superconducting, morphological and structural properties as a function of their position along the pulling direction. X-ray diffraction and SEM analyses show that partial texturing occurs even at very high pulling rates. Each slice has an onset of the critical temperature at /spl sim/90 K Moreover, the critical current densities at 77 K and at 1 Tesla are estimated from dc magnetisation curves in hundreds of A/cm/sup 2/.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.