Effect of SiO2and SiC doping on the powder-in-tube processed MgB2tapes

Effect of SiO 2 and SiC nano-powder doping was investigated for the powder-in-tube processed MgB 2 /Fe tapes. Mg or MgH 2 powder was used as the Mg source of starting materials, and heat treatment was carried out at 600 °C for 1 h. These heat treatment conditions of lower temperature and shorter heating time are advantageous from the aspect of practical production processes. MgH 2 powder improved the connection of MgB 2 grains and prevented oxidation of MgB 2 . SiC and SiO 2 doping greatly enhanced the critical current density ( J C ) values of the tapes prepared with Mg + B powder. However, only the SiC doping was effective in enhancing J C values for MgH 2 + B powder. SiC doping decreased magnetic field sensitivity of J C , while SiO 2 doping did not change the field dependence of J C . The SiC doped tape showed transport J C value of about 6 500 A cm −2 at 4.2 K and in the magnetic field of 12 T. The irreversibility field increased from 17 T to 23 T by the SiC doping.