• Dennis, Anthony R.
• Zou, Jin
• Shi, Yun Hua
• Zhai, Wei
• Fujishiro, Hiroyuki
• Mochizuki, Hidehiko
• Cardwell, David A.
• Namburi, Devendra K.
• Ainslie, Md

Abstract

<p>Large single-grain bulk higherature superconducting materials can trap high magnetic fields in comparison with conventional permanent magnets, making them ideal candidates to develop more compact and efficient devices, such as actuators, magnetic levitation systems, flywheel energy storage systems, and electric machines. However, macrosegregation of Y-211 inclusions in melt-processed Y-Ba-Cu-O (YBCO) limits the macroscopic critical current density of such bulk superconductors, and hence, the potential trapped field. A new fabrication technique using graded precursor powders has recently been developed by our research group, which results in a more uniform distribution of Y-211 particles, in order to further improve the superconducting properties and trapped field capability of such materials. In this paper, experimental results on the pulsed field magnetization of a graded single-grain YBCO bulk sample are presented. Pulsed fields of magnitude up to 5.5 T were applied to the sample, at temperatures of 40 and 65 K. The trapped field profiles indicate that magnetic flux enters the sample in a more uniform manner than standard YBCO samples, resulting in a higher overall trapped field and indicating the success of this processing technique to produce a more homogeneous sample.</p>

Topics

• density
• grain
• inclusion
• melt
• current density
• magnetization