The study of normalized pinning force behavior in Mg_1−xTi_xB₂ superconductor

The critical current density, J_c, for Mg_1−xTi_xB₂ (0 ≤ x ≤ 0.1) samples has been calculated from magnetic hysteresis loop using Bean’s model at different doping level and temperatures.The x = 0.075 sample shows the highest J_c compared with the other Ti-doped samples for all temperatures below 30 K. The reduced field dependence of normalized volume pinning forces has been analyzed at different temperatures and doping level. Fietz et al. and Eisterer scaling procedures have been used to analyze the pinning forces and determine the dominant pinning mechanism in all Ti-doped samples. The grain boundary pinning is found to be the dominant pinning mechanism in all the doped and undoped samples. The magnetic field at the pinning force peak was found to increase with the increase in Ti doping level. Moreover, we observed a suppression of anisotropy from clean to the dirty limit with increasing Ti concentrations.