STUDY ON THE TECHNOLOGY AND PROPERTY FOR Y2BaCuO5 PARTICLE S ARTIFICIAL DOPING TO OBTAIN SINGLE-CRYSTAL DOMAIN MELT-TEXTURED YBCO BULK SUPE RCONDUCTOR

Abstract

This paper describes the method of artificial doping Y-211 phase and melt-textur ed growth with a top-seeded technique to prepare the quasi-single crystal domain YBCO bulk materials with various Y-211 particle contents.The specimens obtained have high density (more than 62g/cm3) and good mechanical toughnes s.The Jc of specimens reaches 123×106A/cm2 u nder 06T at 30K and 135×104A/cm2 under 2 T at 70K.The scanning electron microscope observation of specimens indicates that Y-211 part icles can improve the quality of melt-textured YBCO superconductor and reduce th e microcrack of specimens.Combining the microstructures with Jc measu rements shows that the smaller the particle size,the more homogeneous the partic le distribution,the higher the pinning effectiveness.The best ratio of Y-123 to Y-211 for the superconductor specimens is 1∶05 in moles,in which the Y-211 pa rticles are uniformly distributed and their size is about 200nm.