On the study of phase formation and critical current density in superconducting MgB2

Suchitra Rajput, Sujeet Chaudhary, Subhash C. Kashyap, Pankaj Srivastava
2006 Bulletin of Materials Science  
Superconducting bulk MgB 2 samples have been synthesized by employing sintering technique without using any additional process steps, generally undertaken in view of the substantial loss of magnesium, during heat treatment. Starting with Mg rich powders having different atomic ratios of Mg : B, as against the nominally required Mg : B = 1 : 2 ratio, we have obtained superconducting MgB 2 samples of different characteristics. The effect of excess Mg in the starting mixture and processing
more » ... processing temperature on the phase-formation, transition temperature (T C ) and critical current density (J C ) have been investigated by electrical transport and a.c. susceptibility measurements. The X-ray diffraction and X-ray photoelectron spectroscopic analyses of MgB 2 bulk samples have been carried out to understand the role of excess Mg and the effect of processing temperature. It is established that MgB 2 samples with high critical current density can be synthesized from a Mg rich powder having Mg : B in 2 : 2 ratio, at temperatures around 790°°C. Critical current density has been found to vary systematically with processing temperature.
doi:10.1007/bf02706486 fatcat:445wn2p7sfbnbg332lqigscrc4