Applied superconductivity 1997, vols 1 and 2 issue:158 pages:1587-1590
The presence of a homogeneous distribution of submicron Y2BaCuO5 green phase inclusions strongly enhances the critical currents in melt-textured YBa2Cu3O7. In order to minimize the mean Y2BaCuO5 particle size, a fast melt-processing (FMP) scheme was developed, using cooling rates of 30 degrees C/hour, 120 degrees/hour and 180 degrees/hour during the YBa2Cu3O7 crystal growth. Detailed magnetisation measurements in pulsed fields up to 50 tesla and in the temperature interval of 5K to 77K show a clear decrease of the temperature and field dependence of the critical current J(c) as well as an enhancement of the irreversibilty field H-irr with increasing cooling rate (e.g. H-irr(60K)> 50 tesla at the highest applied cooling rates).