The sheath (3) is a material, which includes an aluminium (Al) matrix, in which nanometric aluminium oxide particles (Al.sub.2O.sub.3) are homogenously dispersed, the content of Al.sub.2O.sub.3 is 0.25 to 5 vol. % and the balance is Al. It is preferred that Al.sub.2O.sub.3 originates from the surface layer present on Al powder used as feedstock material for consolidation. The superconductor based on magnesium diboride (MgB.sub.2) core (1) is fabricated by powder-in-tube or internal magnesium diffusion to boron technology, while the tube is the Al+Al.sub.2O.sub.3 composite, which is a product of powder metallurgy. A loose Al powder is pressed by cold isostatic pressing, and then the powder billet is degassed at elevated temperature and under vacuum, and then is hot extruded into a tube. A thin diffusion barrier (2) tube filled up with a mixture of Mg and B powders or Mg wire surrounded with B powder is placed into the Al+Al.sub.2O.sub.3 composite tube under inert gas or vacuum. Such composite unit is cold worked into a thin wire and then annealed at 625-655 C. for 8-90 min, what results in a formation superconducting MgB.sub.2 in a wire's core (1).

In various embodiments, superconducting wires incorporate diffusion barriers composed of Nb alloys or NbTa alloys that resist internal diffusion and provide superior mechanical strength to the wires.

In various embodiments, superconducting wires incorporate diffusion barriers composed of Nb alloys or NbTa alloys that resist internal diffusion and provide superior mechanical strength to the wires.

In various embodiments, superconducting wires incorporate diffusion barriers composed of Nb alloys or NbTa alloys that resist internal diffusion and provide superior mechanical strength to the wires.

In various embodiments, superconducting wires incorporate diffusion barriers composed of Nb alloys or NbTa alloys that resist internal diffusion and provide superior mechanical strength to the wires.

In various embodiments, superconducting wires incorporate diffusion barriers composed of Ta alloys that resist internal diffusion and provide superior mechanical strength to the wires.

In various embodiments, superconducting wires incorporate diffusion barriers composed of Ta alloys that resist internal diffusion and provide superior mechanical strength to the wires.

A method of manufacturing an insulated superconducting wire material comprising the steps of: removing a flux (S01) by heating a superconducting wire material at a temperature equals to or higher than a flux volatilization temperature and equals to or lower than a heatproof temperature of the superconducting wire material, the superconducting wire material comprising a channel with a channel groove and a superconducting core wire material accommodated in the channel groove of the channel, and the channel groove and the superconducting core wire material being bonded with a solder including the flux; and forming an insulated superconducting wire material (S02) of forming an insulating film on a surface of the superconducting wire material.

A method of manufacturing an insulated superconducting wire material comprising the steps of: removing a flux (S01) by heating a superconducting wire material at a temperature equals to or higher than a flux volatilization temperature and equals to or lower than a heatproof temperature of the superconducting wire material, the superconducting wire material comprising a channel with a channel groove and a superconducting core wire material accommodated in the channel groove of the channel, and the channel groove and the superconducting core wire material being bonded with a solder including the flux; and forming an insulated superconducting wire material (S02) of forming an insulating film on a surface of the superconducting wire material.

In various embodiments, superconducting wires feature assemblies of clad composite filaments and/or stabilized composite filaments embedded within a wire matrix. The wires may include one or more stabilizing elements for improved mechanical properties.