Effect of Addition of TiO2/SiO2 Nanoparticles on Hc2 and Hirr in MgB2 Bulks

In this paper, MgB2 bulks were prepared with doped TiO2 nanoparticles surface-modified by 5-10% SiO2. Quantitative X-ray diffraction (XRD) analysis was performed to obtain the weight fraction of impurities using the Rietveld method. The effects of addition of TiO2/SiO2 nanoparticles on the critical temperature (Tc), the upper critical field (Hc2), and the irreversibility field (Hirr) as a function of doping rates at 750°C are reported. It has been found that the addition of TiO2/SiO2 nanoparticles resulted in small depressions in Tc, while the Hc2 and Hirr performances were improved due to TiO2/SiO2 nanoparticle doping.