Synthesis of RE123 Melt-Solidified Bulks under Low Pressure Pure Oxygen

Abstract

Abstract In general, the superconducting properties of REBa2Cu3O y (RE123: RE= rare earth elements) melt-solidified bulks systematically degrade with an increase in distance from the seed crystal. Our previous study indicated that partial substitution of RE for the barium-site causes the deterioration. Although the crystal growth under reducing atmospheres is effective for suppression of the substitution level of RE for the barium-site, a lot of pores formed by remaining inert gas under reducing atmospheres, resulting in poor mechanical properties. We have attempted to develop RE123 bulks by a new method, melt-solidification under low pressure pure oxygen atmosphere, to suppress substitution of RE for barium and to eliminate pores. The Y123 bulks without pores were successfully fabricated by the new method. The Y123 bulks showed apparently higher J c below 2 T at 77 K than the conventional Y123 bulks melt-solidified in air.