The effect of Ti3SiC2 doping on the microstructure and superconducting properties of MgB2

Doping of MgB2 by Ti3SiC2 and its potential for improving the flux pinning were studied for MgB2(1-x)(Ti3SiC2)x with x = 0, 0.025, 0.05, 0.075 and 0.1, respectively. These bulks were pressed at 20 - 50 MPa and heated to 650 - 950°C for 1.5 - 3 h. It was found that optimal samples were obtained, which were pressed at 40 MPa and sintered at 850°C for 2 h. The transition temperature (Tc) was measured on the optimal series samples using dc susceptibility and a reduction of Tc from 38 K to 36 K was observed. The critical current density (Jc) which was deduced from the hysteresis loop was found to increase at doping levels x = 0.025 - 0.075. With a higher doping level x = 0.1, Jc was suppressed lower than that in the pure one due to non-superconducting precipitates collection at the grain boundaries.