Unusual magnetic properties of a MTG-prepared «123» superconductive ceramic

Bars of YBa2Cu3O7- delta have been sintered by the melt textured growth (MTG) process using Y2Ba1Cu1O5 as a support. The obtained ceramic exhibits a good densification and a high texture. However, one observes an unusual direction of the texture with respect to the temperature gradient. The magnetic properties of the ceramic show that besides the 92 K transition there exists a second one at 50-60 K. These results, and the highly anisotropic magnetic properties of the samples are correlated with electron microscopy observations which show intergrowths near the grain boundaries between '123' and '124' phases. The role of Y2Ba1Cu1O5 as a support is also discussed.