The acceleration of low-temperature sintering of MgB2 bulks with high critical density by minor Sn doping
In the present study, MgB2 bulk was successfully synthesized by Sn-activated sintering at 600 °C for just 5h, exhibiting a dramatic decrease in the sintering time compared to that required for sintering an undoped sample at the same temperature. According to the thermal analysis, a local Mg-Sn liquid formed first during the sintering process and then this prompted the diffusion of Mg into B. As a result, the solid-solid reaction between Mg and B was accelerated and the phase formation of MgB2 was completely achieved at low temperature. The complete formation of the MgB2 phase results in a high Jc of the Sn-doped samples sintered at low temperature. Besides this, the small MgB2 grains and nanoimpurities in the sintered samples also contributed to the good performance as regards Jc. 2010 IOP Publishing Ltd.