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

Bulletin of materials science

Sujeet Chaudhary¹  Subhash C Kashyap¹  Suchitra Rajput¹  Pankaj Srivastava¹ 

[1] Department of Physics, Indian Institute of Technology Delhi, New Delhi 110 016, India$$Department of Physics, Indian Institute of Technology Delhi, New Delhi 110 016, IndiaDepartment of Physics, Indian Institute of Technology Delhi, New Delhi 110 016, India$$

关键词: MgB2;    transition temperature;    X-ray photoelectron spectroscopy.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

Superconducting bulk MgB₂ 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 MgB₂ samples of different characteristics. The effect of excess Mg in the starting mixture and processing temperature on the phase-formation, transition temperature (ð‘�??_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 MgB₂ bulk samples have been carried out to understand the role of excess Mg and the effect of processing temperature. It is established that MgB₂ 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.

【 授权许可】

Unknown