MATERIALS LETTERS, cilt.54, ss.191-199, 2002 (SCI-Expanded)
Bulk YBa2Cu3O7-delta samples, added with TiO2 in the range 0 -10 wt.%, have been prepared by the flame-quench-meltgrowth (FQMG) method and their microstructures have been defined by XRD analysis and optical microscopy, It was found that increasing the content of TiO2 in Y123 from 1% to 5% caused a decrease of superconducting transition temperature, and from 7 to 10 wt.% caused a slight increase of transition temperature, Magnetic measurements in the zero-field-cooled (ZFC) and field-cooled (FC) regimes for different magnetic fields have been performed on these samples in the temperature range 77-300 K using an inductance-meter operating at 1 kHz. Typical repulsive and attractive magnetic forces as a function of distance, and magnetic history between a permanent magnet and YBCO sample cooled with and without magnetic field are described. (C) 2002 Elsevier Science B.V. All rights reserved.