Grain size effects on the superconducting properties of high density bulk MgB₂

Abstract

The liquid Mg infiltration into boron powder preforms appears to be a viable route for the manufacture of large and high density bulk MgB2 products. The key parameters of the technology are discussed together with the morphology of the MgB2 grains resulting in the bulk material. The measured superconducting properties, such as the magnetic field dependence of the critical current density, the persistent current, and the trapped field, as well as the screening properties of cylinder shaped objects, are presented and discussed with regards to the possible power applications.