Investigation of flux jumps during Pulsed Field Magnetization in various MgB2 bulks

Bulk MgB2 superconductors have a promising potential as trapped field magnets, and have a number of attractive properties, such as being rare-earth-free and a low density. However, these superconducting materials have magneto-thermal instabilities visible through flux jumps. These flux jumps occur during conventional magnetization measurements, even at low sweep rates below 10 T/min. In this paper, we investigated the influence of different additions on the flux jumps during Pulsed Field Magnetization (PFM) of MgB2 bulk samples obtained by spark plasma sintering (SPS). PFM experiments are carried out on MgB2 pellets (20 mm diameter and 3.5 mm height) cooled down to an initial temperature of 10 K, 15 K and 20 K. Finally, we discuss the potential of the additions to the MgB2 material in order to avoid flux jumps and increase the resulting trapped field capabilities.