Influence of nanocrystalline boron precursor powder on superconductivity in MgB2 bulk
RIS ID
32552
Abstract
In this report, high-purity nanocrystalline boron powders processed by ball-milling were used as the precursor powders to fabricate MgB2 superconductor. The transport properties and the critical current density in the samples made from ball-milled boron powders and as-supplied boron powders were investigated. It was found that the ball-milled boron powders led to a significant enhancement of the critical current density in MgB2 sintered at 650 °C. The reason can be attributed to the small MgB2 grain size caused by the ball-milled boron precursor powders. The resistivity of the samples made from the ball-milled boron powder was lower than that of the sample from as-supplied boron powder. As the sintering temperature increased, both resistivity and upper critical field decreased in the samples using the ball-milled boron powders as a precursor. Poor connectivity and large strain are responsible for the high resistivity.
Publication Details
Zhang, Y., Lu, C., Zhou, S. Joo, J. (2009). Influence of nanocrystalline boron precursor powder on superconductivity in MgB2 bulk. Journal of Nanoscience and Nanotechnology, 9 (12), 7402-7406.