Phase formation sequences and mechanism of MgB2 superconductor with minor Sn doping

• Published in: Journal of materials science. Materials in electronics 2010, Vol.21 (12), p.1240-1243
• Main Authors: Shi, Q. Z., Jiang, H., Yan, Z. S.
• Format: Article
• Language: English
• Subjects: Borides; Characterization and Evaluation of Materials; Chemistry and Materials Science; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Cuprates superconductors (high tc and insulating parent compounds); Doping; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Magnesium; Magnesium compounds; Materials Science; Melting; Optical and Electronic Materials; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Precipitation; Sintering; Solid-liquid transitions; Specific phase transitions; Superconductivity; Superconductors; Tin
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-009-0053-7

Combined with thermal analysis and phase identification, the phase formation of Sn-doped MgB 2 superconductor during the sintering process were systematically investigated. As compared to the sintering of MgB 2 , the first exothermal peak occurs at a lower temperature, which suggests the accelerated formation of MgB 2 after minor Sn doping. The sintering process of minor Sn-doped MgB 2 orderly underwent the melting of Sn, the reaction between Mg and Sn, the eutectic Mg–Sn reaction, the solid–solid Mg–B reaction, the melting of Mg, the liquid–solid Mg–B reaction and the Sn precipitation. Based on the phase formation mechanism, MgB 2 bulks was successfully synthesized by Sn-activated sintering at 600 °C for only 5 h, exhibiting a dramatic decrease in the sintering time compared to the sintering of undoped MgB 2 .