Comparison of levitation force relative to thickness of disk shaped YBa2Cu3O7-x prepared by MPMG and FQMG processes

Abstract

The precursor YBCO in the stoichiometric ratio of 1:23 were fabricated using the melt-powder-melt-growth (MPMG) technique, and flame-quench-melt-growth (FQMG) technique. The superconducting regions were determined by calculating the levitation force per unit volume as a function of samples' thickness. Our findings indicate that superconductivity forming ratio is sensitive to the preparation techniques and it grows on the surfaces of the samples prepared by FQMG process while it grows in the middle of the samples fabricated by MPMG technique. It was determined that the MPMG process produces more the superconductivity forming ratio than the FQMG method, which is due to platinum impurities. Our results were also checked by polarized optical microscope and XRD pattern. (C) 2009 Elsevier B.V. All rights reserved.