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 degrees C for 1.5 - 3 h. It was found that optimal samples were obtained, which were pressed at 40 MPa and sintered at 850 degrees C for 2 h. The transition temperature (T-c) was measured on the optimal series samples using dc susceptibility and a reduction of T-c from 38 K to 36 K was observed. The critical current density (J(c)) 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, J(c) was suppressed lower than that in the pure one due to non-superconducting precipitates collection at the grain boundaries. (C) 2012 Published by Elsevier B.V. Selection and/or peer-review under responsibility of ISS Program Committee