The influence of the width of the middle magnet in the permanent magnet guideways （PMGs） on the levitation force and the levitation height of single-domain yttrium barium copper oxide （YBCO） bulks has been investigated at 77 K under the zero field cooled （ZFC） state. It is found that the largest levitation force can be obtained in the system with the width of the middle magnet of the PMG equal to the size of the YBCO bulk when the gap between the YBCO bulk and PMG is small. Both larger levitation force and higher levitation height can be obtained in the system with the width of the middle magnet of the PMG larger than the size of the YBCO bulk. The stiffness of the levitation force between the PMG and the YBCO bulk is higher in the system with a smaller width of the middle magnet in the PMG. These results provide an effective way to control the levitation force and the levitation height for the superconducting maglev design and applications.
Top seeded infiltration and growth technique (TSIG) is an effective method for the preparation of high quality large YBa2Cu3O7-x (YBCO) bulk superconductors. In this paper, single domain YBCO bulk superconductors, with different Y2Ba4CuWOy (YW2411) additions, have been fabricated by TSIG process. the solid phase pellet is made of a mixture of Y2BaCuO5(Y211) + xwt% YW2411 powders, x=0, 1, 3, 5, 7, 9. The growth morphology, microstructure and levitation force of the YBCO bulks have been investigated, it is found that the levitation force is increasing from 23.05 to 33.6 N with the increasing of YW2411 addition from 0 to 5wt%, and decreasing from 33.6 to 21.59 N with the increasing of YW2411 addition from 5 to 9wt%,the largest levitation force is obtained when the YW2411 content is about 5wt%. This is very important for us to fabricate high quality YBCO bulk superconductors.
Wan Feng, Yang Wanmin, Li Guozheng, Song Fang, Gao Ping, Liang Wei Shaanxi Normal University, Xi’an 710062, China
The top-seeded infiltration and growth process (TSIG) is an important method to fabricate YBCO bulk superconductors. In this paper, single domain YBCO superconductors with different Gd2Ba4CuWOx (GdW2411) additions have been fabricated by TSIG process, the amount of GdW2411 added to Y2BaCuO5 (Y211) is in the range from 0wt% to 8 wt%, but there is no other additions to the liquid source. The growth morphology, microstructure and levitation force of the YBCO bulks have been investigated, it is found that the levitation force is increasing from 14 to 25 N with the increasing of GdW2411 addition from 0 to 4 wt%, and decreasing from 25 to 7 N with the increasing of GdW2411 addition from 4 to 8 wt%, the largest levitation force is obtained when the GdW2411 content is about 4 wt%. This is helpful for the fabrication of high quality YBCO bulk superconductors.
Song Fang, Yang Wanmin, Wang Miao, Li Guozheng, Wan Feng, Gao Ping, Liang Wei Shaanxi Normal University, Xi’an 710062, China
