Flux jump behaviors and mechanism of FeTi doped MgB2 at 5Â K

This study examined the flux jump behaviors of Fe-doped MgB2 according to content of FeTi particles at 5 K, at which flux jump has been shown to be more frequent. The samples were synthesized in a stainless steel tube with Mg, B and FeTi particles. The motives of flux jump in MgB2 superconductors are over-moving fluxes around the defects and the low heat capacity of MgB2. MgB2 was doped with FeTi particles to overcome these vulnerable points of MgB2. The flux jump of MgB2 decreased with increasing content of doped FeTi particles. On the other hand, excessive doping of FeTi resulted in a decrease of diamagnetic properties and the flux pinning effects together. It is concluded that FeTi particles in MgB2 do not block the flux jump itself, but the propagation of flux jump of MgB2.