Critical current density in the MgB2 nanoparticles prepared under autogenic pressure at elevated temperature

This Letter reports on obtaining MgB2 nanoparticles revealing an intra-granular enhanced critical current density (JC ⩾ 108 A/cm2) for the undoped sample. A rapid, single-stage, high yield, reproducible, straightforward, scalable, and competent approach at 750 °C is described herein for the synthesis of superconducting MgB2 nanoparticles. The magnetization studies indicated clearly the existence of bulk superconductivity in MgB2 nanoparticles at TC ∼ 38 K. Electron spin resonance and microwave absorption study substantiated the paramagnetic nature of the MgB2 nanoparticles in the normal state. The plausible reaction mechanism leading to the formation of MgB2 is explained.