Magneto-optical and microstructural investigations on KClO3-doped YBCOHTSC

The influence of KClO3 addition on the magnetic properties and microstructu re of YBCO HTSC materials with nominal composition (A): YiBa2-xCu3Oy, (B): Y1-0.2xBa2-0.2xKxCu3Oy (C): Y1Ba2Cu3.5-xKxOy (x = 0-0.75) were investigated . Magneto-optic imaging of flux distributions was employed to study the gra in connectivity in the doped and undoped samples in a direct way. The obtai ned flux patterns taken at various temperatures reveal that KClO3-doped sam ples (x = 0.30) exhibit flux distributions being close to those being obser ved in melt-textured superconductors. This demonstrates that the grain conn ectivity in the doped samples is considerably improved as compared to pure ones, which is an important issue for the fabrication of coated conductors of YBCO. (C) 2001 Elsevier Science B.V. All rights reserved.