The effects of nano-scale iron doping on superconductivity and microstructure of MgB2 bulk

• Main Authors: Ye Yang, Chuan Ke, Lei Wang, Huihui Sun, Cuihua Cheng, Yong Zhao
• Format: Conference Proceeding
• Language: English
• Subjects: critical current density; Doping; Flux pinning; Iron; irreversibility field; Magnesium compounds; MgB 2; Microstructure; Nanoscale devices; Solid state circuits; Superconducting filaments and wires; Superconducting materials; Superconductivity
• DOI: 10.1109/ASEMD.2009.5306637

Mg 1-x Fe x B 2 superconductor was prepared by in situ solid state reaction to study the effects of nano-iron doping on the superconductivity of MgB 2 . Two kinds of nano-iron sources were used: nano-iron particles and nano-iron wires. It was found that crystal structure was not affected by nano-iron doping for either form of dopant source. T c , J c , and H irr were severely suppressed by iron nano-particles doping. In contrast, with iron nano-wires doping, T c of the MgB 2 superconductors were not changed remarkably, while their J c and H irr were slightly enhanced at all the temperature ranges investigated in this work. Under 4 T field, the sample doped with 1% wt iron nano-wires reached the highest J c of 1.1 times 10 4 A/cm 2 at 10 K and 2.2 times10 2 A/cm 2 at 20 K, respectively. It was argued that the Fe nano-wires may be introduced into MgB 2 as external pinning centers in high field region.