Structure and critical current of Ni-sheathed PIT MgB2 tapes with In metal powder addition

Effects of Metal (Ag, Sn and Zn) Nanoparticles Inserted into MgB₂ Grain Boundaries on Transport and Superconducting Properties

“…For example, the J c value of Zn(2h), which was maximum within all coated MgB 2 , was 1.5 times that of the bare MgB 2 . Similar enhancement of J c values have been reported previously; 9,10) however the previously reported enhancement factor was relatively large. In previous reports, 9,10) the metal added to MgB 2 not only improved the intergranular connectivity between MgB 2 grains but also increased the packing factor for MgB 2 /metal composite.…”

“…Tachikawa et al reported that adding Ag or Sn metals to MgB 2 powder improved connectivity between MgB 2 grains without annealing. 9,10) Moreover, they also reported that future improvement was observed by annealing at a moderate temperature of 473 K. These results ascribed that metal addition linked MgB 2 grains, thus improving connectivity. This method seems to be effective to the preparation of superconducting wires.…”

“…As the result, the metal that is only utilized for grain linkage is expected to reduce the amount of metal required in previous reports. 9,10) Several techniques have been developed to coat powder particles with a metal layer.…”

“…Since soft metals are suitable, 9,10) Ag, Zn and Sn were selected as the coating metal. MgB 2 and Ag, Zn and Sn systems have been previously reported in several studies; however these studies focused on MgB 2 and metal alloys such as (Mg 1¹x A x )B 2 (A = Ag, 2129) Zn 3036) and Sn 3740) ).…”

“…There are rather a few studies on the superconducting properties of MgB 2 mixed with metals without alloying. 9,10) In this paper, using prepared MgB 2 powder coated with metallic Ag, Zn or Sn, the structural, transport and superconducting properties of composite MgB 2 /metal were evaluated. Moreover a portion of the composite MgB 2 /metal was annealed at a moderate temperature.…”