Study of the influence of the processing rate on the directionally solidified YBaCuO

Directional solidification technique with sample transport in a thermal gradient is used for fabrication of melt textured superconducting YBaCuO bars. Recent developments of the processing for this material are reported. The paper will analyze the influence of the high processing rates (in particular using pulling rate in the furnace up to 4 cm/h) both on the microstructure and on the superconducting properties. Morphological and structural analyses show aligned grains also for samples fabricated with such high pulling rates. From characterizations performed by ac susceptibility measurements and de magnetization curves results that the onset of superconductivity is 91 K and the critical current density at T = 77 K and at zero magnetic field is about 5000 A/cm(2). These preliminary results indicate that the quality of these Y123 samples appears comparable to (Nd,Sm)-based superconductors grown using similar processing conditions.