Growth of large PrBa2Cu3O7-delta single crystals by modified TSSG method using zirconium dioxide crucibles

Bulk PrBa2Cu3O7-delta single crystals of 2.5g weight were seed-grown by mod ified TSSG technique using yttria stabilized zirconium dioxide crucibles. A chemical composition analysis revealed a visible yttrium substitution (fro m the seed and crucible material) of Pr atoms to x = 0.2-0.3 in the Pr1-xYx Ba2Cu3O7-delta formula. Neutron diffraction and X-ray diffraction measureme nts showed the block structure of different disorientation along the [0 0 1 ]- and [1 0 0]-directions. FWHM of the rocking curve on (0 0 6) reflection is 0.9 degrees by neutron diffraction and 0.5 degrees by X-ray diffraction. FWHM of the rocking curve on a (200) reflection is 0.3 degrees by X-ray di ffraction. The antiferromagnetic ordering of Pr magnetic moments was found at a temperature T-N = 11 K by neutron diffraction. It was attempted to cha nge the cation distribution and to increase the c-lattice parameter in a Pr 123 crystal by fast crystallization. At a cooling rate of 200 K/s the c-par ameter increased from 11.68 to 11.75 Angstrom, which is insufficient for a possible appearance of superconductivity in this crystal. (C) 2000 Elsevier Science B.V. All rights reserved.