Effect of addition of TiO2/SiO2 nanoparticles on Hc2 and Hirr in MgB2 bulks

Abstract

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 (T_c), the upper critical field (H_c2), and the irreversibility field (H_irr) as a function of doping rates at 750degC are reported. It has been found that the addition of TiO₂/SiO₂ nanoparticles resulted in small depressions in T_c, while the Hc₂ and H_irr performances were improved due to TiO₂/SiO₂ nanoparticle doping.