Magnetic and superconducting properties of Gd1-xPrxBa2Cu3O7-y single crystals

Magnetic and superconducting properties were studied for high quality Al-fr ee orthorhombic Gd1-xPrxBa2Cu3O7-y single crystals (0 less than or equal to x less than or equal to 1.0) grown by the flux method. An indication of th e interaction between Pr and Cu(2) magnetic sublattices was found for nonsu perconducting Pr123. Different sign of magnetic anisotropy was established for the Pr and Gd ions at low T for crystals with x = 0.6 and 0.44. It was also shown that the superconductivity reported by Zou et al, [Phys. Rev. Le tt. 80, 1074 (1998)] for Pr123 single crystals grown by TSFZ method seems t o be connected with partial substitution of Ba for the Pr-sites.