Thick film biaxially textured YBCO coated tape conductors prepared using magnetic grain alignment

We report a new approach to the preparation of biaxially textured YBCO coat ed tape conductors. Using a dynamic magnetic grain alignment technique, a b iaxially aligned dispersion of orthorhombic Y-247 powder is settled on unte xtured silver substrates, In subsequent heat treatment the Y-247 is transfo rmed to Y-123 and CuO involving a partial melt. Critical current densities at 77 K in self-field of up to 5000 A/cm(2) have been obtained in films fro m 10 to 30 pm thick. There is a clear enhancement of J(c) relative to ident ically prepared untextured or uniaxially textured samples. J(c) appears to be limited at present by the difficulty of achieving fully densified films while retaining biaxial texture. Provided significant improvements in J(c) can be obtained this method offers an alternative to coated tape processes based on epitaxial growth which does not demand textured substrates and can give much higher fill factors. The grain alignment technique is quite gene ral for materials with anisotropic magnetic or electric susceptibility and can therefore be utilised in a wide range of applications.