CRYSTAL-GROWTH OF REBA2CU3O7-Y (RE=Y, LA, PR, ND AND SM) BY THE TRAVELING-SOLVENT FLOATING-ZONE METHOD

Single crystals of REBa2Cu3O7-y, (RE = Y, La, Pr, Nd and Sm) have been grown successfully by the travelling-solvent floating-zone (TSFZ) method. The maximum dimensions of the grown boules were 6 mm empty set X 27 mm. It is shown that the density of the feed rod and atmosphere are the crucial variables for a successful growth procedure. The grown crystals were identified to be single-crystal REBa2Cu3O7-y by Laue X-ray measurements and X-ray powder diffraction. The maximum area of the grains was about 1 X 1 mm2 for the Y system, 1.5 x 1.5 mm2 for the La, Pr and Nd systems and 1.5 X 3 mm2 for the Sm system, respectively. Superconducting transitions of crystals annealed in oxygen typically occur at 91.5 K, 90 K, 91 K and 94 K for the Y, La, Nd and Sm compounds, respectively.