Development of Ag sheathed Bi-2223 multifilamentary tapes with MgO coated filaments

A dip-coating process to obtain controlled, uniform coatings on silver sheathed Bi-2223 wires suitable for the fabrication of multifilamentary tapes is reported. Tapes with continuous fully connected MgO resistive barrier layers 1 to 17 /spl mu/m thick have been produced and characterized. The correlation between their microstructure, electric transport and magnetic properties has been analyzed. An effective reduction of the interfilamentary coupling with a minimum degradation of the tape performance has been obtained for 1 to 3 /spl mu/m thick barrier layers.