Effect of addition of nanoparticle TiO2/SiO2 on the superconducting properties of MgB2

In this paper, bulk MgB2 was prepared by doping with nanoparticle TiO2 surface-modified by 5-10% SiO2. The doping ratio of TiO2/SiO2 to MgB2 was 0, 5, 10, and 15 wt%. The sintering temperature varied from 650 °C to 950 °C. Quantitative X-ray diffraction (XRD) analysis was performed to obtain the lattice constants and the weight fraction of impurities using the Rietveld method. It was found that the critical temperature (Tc) increases with the lattice constants. The critical current density (Jc) is affected by the doping ratio and the sintering temperature. The Jc exhibited the highest value at the doping ratio of 10 wt% for 5 K and 20 K and at the doping ratio of 5 wt% for 30 K, when the sintering temperature was fixed at 750 °C. When the doping ratio was fixed at 5 wt%, the samples with the sintering temperature of 750 °C had the best Jc for 5 K and 20 K, while the sample with the sintering temperature of 850 °C exhibited the highest Jc at 30 K.