Melt-processing of Nd(123)-based composites in air

Full text: Large, bar-shaped, single domains of pure [Nd (123)] and the composite [Nd (123) + 10wt. % Nd (422)], have been fabricated in air using a melt-processing technique. After 880 hours of annealing in pure oxygen, both samples exhibited Tc values > 91 K, while the transition into the superconducting state was not sharp in all cases. Magnetization measurements carried out at 77 K over the magnetic field range [0- 1 T], showed no indication of the formation of the second peak effect in the M-H loops for either sample. Compared to the undoped Nd(123) material, the Jc of the Nd(422) doped sample is very high (> 10 000 A/cm2), suggesting that the addition of excess Nd(422) phase significantly enhances its performance and contributes to the flux-pinning mechanism. A study is being carried out to investigate the magnetic and transportation properties of these samples under larger magnetic fields