Effect of addition of nanoparticle TiO 2/SiO 2 on the superconducting properties of MgB 2

Abstract

In this paper, bulk MgB 2 was prepared by doping with nanoparticle TiO 2 surface-modified by 5–10% SiO 2. The doping ratio of TiO 2/SiO 2 to MgB 2 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 ( T c) increases with the lattice constants. The critical current density ( J c) is affected by the doping ratio and the sintering temperature. The J c 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 J c for 5 K and 20 K, while the sample with the sintering temperature of 850 °C exhibited the highest J c at 30 K.