Thermodynamically controlled melt processing to improve bulk materials

High quality melt textured YBCO samples have been prepared on a modified MTG route, a trapped magnetic field of 8.5 T at 51.5 K was measured in the gap of 1 mm in a mini-magnet from two YBCO cylinders (d = 26 mm, h = 12 mm). at 77 K, each single domain cylinder traps more than 600 mT and the levitation pressure of 15 N/cm(2) in a distance of 0.5 mm was achieved by a 0.4 T SmCo magnet, The thermodynamic background of the preparation method is outlined. A thermodynamic approach to control growth and stoichiometry y in the alternative material Nd1+yBa2-yCu3Ox is discussed. Critical currents of 46 kA/cm(2) (77K) have been achieved by a modified recipe.