Impurity effects on activation energy, structure and physical properties of Ybco superconductor

The influence of separately added 0.3 wt%, CdO, Bi2O3, BeO and SiO2 on the phase formation, microstructure, magnetic transport properties Y1Ba2Cu3O(7-$\delta$) (Y-123 or YBCO) fabricated by conventional solid state reaction method has been analyzed. results reveal a very low solubility limit for bismuth silicon in Y-123 phase, leading to precipitation phases located within intergranular regions. addition suppresses granular nature structure probably incorporating into host matrix. CdO does not have remarkable effect both structural superconducting at this doping ratio. Attractive infield transition behavior was obtained Bi2O3 sample with narrower width an increase temperatures approximately 1 K. activation energy (U0), potential barrier prevent flux flow, samples estimated taking account Arrhenius law. best U0 value computed be 1.11 eV belonging which implies contribution 3-5 µm sized Bi containing regions pinning capability Y-123.