纳米CeO_(2)掺杂的YBCO超导块材的制备及其性能  

Fabrication and properties of nano-CeO_(2)doped Y-Ba-Cu-O bulk superconductors

作　　者：李国政 王妙 Li Guo-Zheng;Wang Miao(College of Physics and Materials Science,Tianjin Normal University,Tianjin 300387,China;School of Science,Xi’an Aeronautical University,Xi’an 710077,China)

机构地区：[1]天津师范大学物理与材料科学学院,天津300387 [2]西安航空学院理学院,西安710077

出　　处：《物理学报》2024年第19期278-284,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51872199)资助的课题。

摘　　要：本文采用两种熔渗生长工艺(011-IG和211-IG)制备纳米CeO_(2)掺杂的Y-Ba-Cu-O(YBCO)超导块材,同时使用一种坑式籽晶模式来阻止薄膜籽晶在热处理过程中的移动,随后对样品的生长形貌、微观结构和超导性能进行研究.结果表明,在低掺杂量(质量分数为1%)下,YBCO晶体的正常生长不会受到影响,用两种工艺均能成功制备生长完全的单畴YBCO超导块材,且籽晶的位置没有发生任何移动,证明了新籽晶模式的有效性.扫描电子显微镜结果表明,纳米CeO_(2)掺杂可以有效细化超导块材内Y_(2)BaCuO_(5)(Y-211)微米级粒子的尺寸,且该方法对两种工艺均有效.低温磁性测试结果表明,011-IG法制备的纳米CeO_(2)掺杂的样品在低外场下呈现出比未掺杂样品明显优越的J_(c)性能,说明细化的Y-211粒子可以有效地提高δl型钉扎.此外,相比211-IG法制备的样品,011-IG法制备的样品在磁悬浮力、微观形貌和J_(c)性能等方面表现更优越,因此011-IG法是一种更有潜力的制备工艺.本文结果对进一步提高YBCO超导块材的性能和优化制备工艺有重要意义.Single-domain Y-Ba-Cu-O(YBCO)bulk superconductors can be widely used in the superconducting maglev,cryomagnets,motors/generators fields.In order to improve the performance of the YBCO bulk superconductors further,in this work,nano-CeO_(2)doped YBCO bulk superconductors are fabricated by two infiltration growth techniques(011-IG and 211-IG)respectively,in which two solid pellets of compositions Y_(e)O_(3)+1.15BaCuO_(2)+0.1CuO+1wt.%nano-CeO_(2)and Y_(2)BaCuO_(5)(Y-211)+1wt.%nano-CeO_(2)are employed.And a novel pit-type seeding mode is used to prevent the film seed from moving in the heat treatment process,then the growth morphologies,microstructures and superconducting properties of the samples are investigated.The results show that at a low doping level(1 wt.%),the normal growth of the YBCO crystal is not affected,and fully-grown single-domain YBCO bulk superconductors can be successfully prepared by the two techniques.Furthermore,the positions of the seeds do not move at all,which proves the effectiveness of the new seeding mode.The perpendicular growth sector boundaries on the top surfaces of the samples and clear(00l)series X-ray diffraction(XRD)peaks both prove the high c-axis orientations and high growth quality of the samples.The scanning electron microscopy(SEM)results indicate that the nano-CeO_(2)doping can effectively refine the sizes of the Y-211 micro-particles in the bulk superconductors,and this method is applicable to both techniques.Low-temperature magnetization measurement shows that the nano-CeO_(2)doped sample prepared by the 011-IG method shows obviously better J_(c)property than the undoped sample at low fields,indicating that the refined Y-211 particles can effectively enhance theδl-type pinning.In addition,compared with the 211-IG-processed sample,the 011-IG-processed sample performs better in terms of levitation force,microstructure and J_(c)property,thus the 011-IG method is a more promising preparation process.The results of this study are important in improving the performance of the YB

关 键 词：单畴Y-Ba-Cu-O 熔渗生长 纳米CeO_(2)掺杂 超导性能 

分 类 号：O511.3[一般工业技术—材料科学与工程]