Trapping Magnetic Field in Bulk Iron-based Superconductor Sintered under High Pressure

Abstract We fabricated two bulk superconductors of (Ba,Na)Fe 2 As using a cubic press and hot sintering technique. For #1 sintered by press, despite its small dimensions, with diameter 4.1 mm height 3.64 mm, trapped field value ~9.97 kG has been achieved on surface, which is only 230 G lower than the reported in 10 before. Critical current density ( J c ) estimated to be 81.2 kA cm −2 at 4.2 K under self-field, larger It suggests that improvement high pressure could make up for negative influence from smaller dimensions achieve large field. In second #2 pressing technique, 9.45 4.58 ~ 33.9 ~8.81 surface. The expected better texturing not observed. Possible origins inferior properties are discussed.