Superconducting properties of MgB_(2) films electroplated to stainless steel substrates

摘要

Superconducting MgB_(2) films have been fabricated on stainless steel substrates by means of electroplating in a molten electrolyte composed of MgCl_(2), MgB_(2)O_(4), NaCl, and KCl containing a fractional amount of CuCl_(2). Microscopic observation has revealed that the electroplated films and substrates are combined with each other through Cu-rich layers at the interfaces. Transport measurements have shown that the electroplated MgB_(2) films possess an upper critical field, H_(c2)(0), of 28 T, an irreversibility field, H_(irr)(0), of 13 T, and a critical current density, J_(c)(5 K,0 T), of 25 000 A/cm~(2), which suggests that the electroplating in molten salts is a promising alternative to the powder-in-tube method for the fabrication of MgB_(2) tapes.