Enhancement of critical current density in glycine-doped MgB2 bulks
Samples of MgB 2 + x wt% glycine (with x = 0, 2, 5 and 8) were sintered at 800 °C for 30 min. Obvious enhancement of critical current density (J c) over the entire field was obtained in 5 wt% glycine-doped sample, indicating that grain connectivity and pinning effect were both improved. The improvement of J c was attributed to the pinning effect by C substitution, MgO nano-particles, and relatively smaller MgB 2 grains. Besides, 2 wt% glycine could only improve J c at low field, while excessive glycine (above 5 wt%) would lead to unfavorable J c performance. 2012 Elsevier B.V. All rights reserved.