Y-211粒子与Y_(2)O_(3)粉掺杂的熔融织构YBCO超导体性能及微观研究

Study on the Performances and Microstructure for Y_(2)BaCuO_(5)Particles and Y_(2)O_(3)Powder Artifical Doping to Melt-Textured YBCO Bulk Superconductor

采用熔融织构法结合顶部籽晶技术 ,掺杂 Y2 O3粉和 Y- 2 1 1粒子制备了高质量的准单畴熔融织构的 YBCO块材。样品的 Jc测量表明 :临界电流密度 Jc在 1 0 K温度 0 .6T磁场下达到 1 .6×1 0 6 A/ cm2 ;在 70 K温度 2 T磁场下达到 1 .2 4× 1 0 4A/ cm2。扫描电镜观察表明 :掺杂 Y2 O3粉所形成的 Y- 2 1 1粒子是柱状的 ,而掺杂 Y- 2 1 1粒子在母体材料中形成的是球形的 Y- 2 1 1粒子 ,掺杂Y2 O3 粉比 Y- 2 1 1粒子能更有效地改善样品的生长状况。可见 ,Y- 2 1 1粒子与超导母体材料之间的界面对磁通钉扎起主要作用 ,Y- 2 1

This paper describes the method of artificial doping Y-211 phase and Y 2O 3 powder for melt-textured growth (MTG) with a topseeded technique to prepare the quasi-single crystal domain YBCO bulk materials. The J c of specimens reaches 1.6×10 6A/cm 2 under 0.6 Tesla at 10K and 1.24×10 4A/cm 2 under 2 Tesla at 70K. The SEM observation of specimens indicates that doping of Y 2O 3 powder is more effective than that of Y-211 particles in improving the growth quality of Melt-textured YBCO superconductor and in reducing the microcrack of specimens, because doping the Y 2O 3 powder forms the columnar Y-211 particles, while doping the Y-211 particles directly to matrix materials forms the spherical Y-211 particles, Combining the microstructures with J c measurements shows that the interfaces between the Y-211 particles and the Y-123 matrix materials are most important on flux bundle pinning, in which the gradient of free energy is larger than that of other places.