Bi 2212 tapes prepared by alternating electro-deposition and heat treatments

Bi 2212 tapes have been prepared by oxidation reaction of 3.5 micrometer thick precursor layers deposited electrolytically in a sequential way on both sides of a 50 micrometer thick Ag tape. Intermediate heat treatments were performed to improve the adhesion of the deposited precursors and to benefit of the homogenisation brought about by the presence of liquid phases. After the last deposition sequence, a 2 step heat treatment was carried out to allow for Bi 2212 to synthesis and texture via a partial melt growth process, modified in such a way that the specimens were held for a few minutes only above the peritectic melting point of the Bi 2212 phase. It was found that Bi 2212 crystallises into platelet like grains giving an excellent texture, but in some places the perfect alignment of these platelets with the substrate was hindered by the presence of cuprates. However, since our layers are typically one order of magnitude thinner than those usually prepared with the conventional partial-melt growth technique, cuprates are smaller leading to transport Jc values among the best. Moreover, the total preparation time is only 4 h. Our best transport Jc measured on a short length is 3,5x10(4) A/cm(2) at 77K and 3x10(5) A/cm(2) at 4.2 K which correspond to respectively 7.35 and 63 A for a specimen of 3 mm in width.