Influence of passage of electric current on composition and properties of high temperature superconducting ceramics YBa2Cu3O6,5+δ

Changes of composition of YBa2Cu3O6,5+δ ceramics after passing constant and alternating electric current at 77 K were investigated. Sufficient changes of cation composition and concentration of active oxygen δ, caused by constant current, were revealed for the first time. Element redistribution both over sample length and between volume and surface was noted. Migration of sulfur, silicon, potassium and chlorine impurities was observed. Changes of composition were accompanied by decrease of values of critical current density, especially in the region of positive electrode