Superconducting MgB2/Ta tapes with a critical temperature of 34K were prepared successfully by ex situ annealing of electrophoresis-grown B in the presence of Mg vapour at 920C. Scanning electron microscopy was used to examine the surface morphology of the MgB2/Ta tapes, and well-formed MgB2 crystals with sizes up to 2μm were observed. The X-ray diffraction patterns exhibited randomly orientated growth of MgB2 phase in the tapes. Estimates using hysteresis loops and the Bean model gave a value of 6.8 x 105A/cm2 for the critical current density.

Preparation of MgB2 Superconducting Tapes using Electrophoresis. J.D.Xu, S.F.Wang, Y.B.Zhou, Y.L.Zhou, Z.H.Chen, D.F.Cui, H.B.Lu, M.He, S.Y.Dai, G.Z.Yang: Superconductor Science and Technology, 2002, 15, 1190-2