中文摘要：

本文介绍了沿C轴方向排布复层籽晶制备YBCO超导单畴的方法．该方法能够使123晶畴在不同深度进行生长．通过c轴方向籽晶的排布，研究了YBCO单畴中的（001）／（001）晶界．虽然由于压模中籽晶n6面的倾斜，造成部分（001）／（001）晶界出现大角晶界，使晶界上残余有液相，但仍有晶界连接良好、晶界上不存在残余液相和211粒子、错配角小于5°的（001）／（001）晶界的形成．对于制备有深度要求的单畴块材，复层籽晶法是一种有效的生长方法．在定向控制好籽晶方向的条件下，该方法可以提高超导单畴的生长深度．在77K，0．5T下，测试该样品磁悬浮力达到37N．

英文摘要：

A new Multi-Seeds along c-axis Powder Melting Process （MSPMP） of fabricating bulk YBCO super- conductor single domain is reported. The Multi-Seeds technique aims to increase the height of single domain. It can make the 123 grain grown at different place along c-axis in bulk YBCO. Although a few of large angle grain bounda- ry are formed as the Nd123 seeds orientation inclined in pressure dwell. A well （00 1）/（001） grain boundary is also formed by this multi-seeds technique, and the mis-orientation angle of （00 1-）/（001） grain boundary is smaller than 5 with optical microscopic investigation. The （00 1）/（001） grain boundary is connected well without residual liquid phase and rich 211 particles deposited. The 20mm-depth bulk YBCO domain in c-axis is obtained. It is concluded that the multi-seeding process has an effective function on increasing YBCO single domain growth depth if the Nd123 seed orientated well in pressure dwell. At 77K, in 0.5T magnetic field, with zero filed cooling in liquid nitrogen, the levitation force of the multi-seeds YBCO single domain is measured to 37N.