Improved Jc of MgB2 superconductor by ball milling using different media

In this paper, the effects of ball milling B powders using different media, such as acetone, ethanol, and toluene on the superconducting properties of MgB2 have been studied. It was observed that toluene medium was the most effective of them all for enhancing Jc. Jc was estimated to be 5 x 103 A/cm2 at 8 T and 5 K. This value is much higher than that of pure MgB2 that was not ball milled, by a factor of 20. It was considered that ball-milled B using toluene leads to smaller MgB2 grains, resulting in enhanced Jc at low operating temperature and high field.