Title :
Comparative studies of MgB2/Mg nano-composites and press-sintered MgB2 pellets
Author :
Li, Qiang ; Wu, L. ; Zhu, Y. ; Moodenbaugh, A.R. ; Gu, G.D. ; Suenaga, M. ; Ye, Z.X. ; Fischer, D.A.
Author_Institution :
Brookhaven Nat. Lab., Upton, NY, USA
fDate :
6/1/2003 12:00:00 AM
Abstract :
We present our studies of superconducting and microstructural properties of bulk MgB2/Mg nano-composites and press-sintered MgB2. TEM investigation revealed that the composites are very dense, consisting of nano-sized MgB2 grains connected by the well-defined clean grain boundaries (GB). Both amorphous and structural intact GB´s were observed in the press-sintered samples. Magnetization and transport measurements showed that the composite carried over 1 MA/cm2 critical current density (Jc) at 5 K and self-field, while the pressed sintered MgB2 has Jc ∼ 0.25 MA/cm2 at 5 K and self-field. The origin of substantially higher Jc found in the composites is mostly due to their nano-sized grains and clean grain boundaries.
Keywords :
critical current density (superconductivity); grain boundaries; magnesium; magnesium compounds; magnetisation; nanocomposites; sintering; transmission electron microscopy; type II superconductors; 5 K; MgB2; MgB2-Mg; MgB2/Mg nanocomposites; TEM; critical current density; dense; magnetization; press-sintered MgB2 pellets; self-field; transport measurements; well-defined clean grain boundaries; Amorphous materials; Flux pinning; Furnaces; Grain boundaries; Magnetization; Powders; Superconducting filaments and wires; Superconducting transmission lines; Temperature; Type II superconductors;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2003.812070
