Abstract: Provided is a method for manufacturing a base material powder having a carbon nanocoating layer, the method including adding a polycyclic aromatic hydrocarbon to a base material powder, heating the mixture to a temperature that is higher than or equal to the boiling point of the polycyclic aromatic hydrocarbon and is lower than or equal to the relevant boiling point temperature+300° C., and that is higher than or equal to the thermal decomposition temperature of the polycyclic aromatic hydrocarbon, and thereby coating the surface of the base material powder with a layer of carbon having a thickness of 0.1 nm to 10 nm.

Abstract: Provided is a method for manufacturing a base material powder having a carbon nanocoating layer, the method including adding a polycyclic aromatic hydrocarbon to a base material powder, heating the mixture to a temperature that is higher than or equal to the boiling point of the polycyclic aromatic hydrocarbon and is lower than or equal to the relevant boiling point temperature +300° C., and that is higher than or equal to the thermal decomposition temperature of the polycyclic aromatic hydrocarbon, and thereby coating the surface of the base material powder with a layer of carbon having a thickness of 0.1 nm to 10 nm.

Abstract: Provided are a method for manufacturing MgB2 superconductor by pressure molding a mixture of Mg powder or MgH2 powder and B powder and heat-treating the mixture, the method including (I) a step of adding a polycyclic aromatic hydrocarbon to the B powder, while heating the mixture to a temperature higher to or equal to the melting point of the polycyclic aromatic hydrocarbon at the time of this addition, and thereby covering the surface of the B powder with the polycyclic aromatic hydrocarbon; and (II) a step of mixing the B powder having the surface covered with the polycyclic aromatic hydrocarbon, with the Mg powder or the MgH2 powder, or a step of combining the B powder having the surface covered with the polycyclic aromatic hydrocarbon, with an Mg rod; and an MgB2 superconducting wire which has high critical current density (Jc) characteristics and less fluctuation in the critical current density (Jc).

Abstract: Provided are a method for manufacturing MgB2 superconductor by pressure molding a mixture of Mg powder or MgH2 powder and B powder and heat-treating the mixture, the method including (I) a step of adding a polycyclic aromatic hydrocarbon to the B powder, while heating the mixture to a temperature higher to or equal to the melting point of the polycyclic aromatic hydrocarbon at the time of this addition, and thereby covering the surface of the B powder with the polycyclic aromatic hydrocarbon; and (II) a step of mixing the B powder having the surface covered with the polycyclic aromatic hydrocarbon, with the Mg powder or the MgH2 powder, or a step of combining the B powder having the surface covered with the polycyclic aromatic hydrocarbon, with an Mg rod; and an MgB2 superconducting wire which has high critical current density (Jc) characteristics and less fluctuation in the critical current density (Jc).

Abstract: Disclosed is an iron-based superconducting wire comprising a tubular material formed mainly from iron, and an iron-based superconductor formed in the tubular material, wherein the iron-based superconductor contains the iron forming the tubular material as a chemical constituent element of the iron-based superconductor.

Abstract: Disclosed is an iron-based superconducting wire comprising a tubular material formed mainly from iron, and an iron-based superconductor formed in the tubular material, wherein the iron-based superconductor contains the iron forming the tubular material as a chemical constituent element of the iron-based superconductor.

Abstract: In a fabrication method of a MgB2 superconducting tape and wire by filling a tube with a MgB2 superconducting powder and forming it into a tape or wire, a fabrication method of a MgB2 superconducting tape (and wire) which is characterized by using a MgB2 superconducting powder having a high critical current density (Jc) owing to its lowered crystallinity and having potential for excellent grain connectivity as the MgB2 superconducting powder. Provided are a fabrication method of a MgB2 superconducting tape and wire which can fabricate a MgB2 superconducting tape and wire having a level of Jc sufficiently high for practical applications and homogeneous quality throughout its length by an ex-situ process employing a material of the composition suitable for its working environment as the sheath material, and a MgB2 superconducting tape and wire thereby fabricated.

Abstract: The present invention provides a method for producing a MgB2 superconductor, comprising compacting and heating a mixture comprising Mg or MgH2 powder and B powder, wherein said mixture comprises SiC powder and an aromatic hydrocarbon, and a MgB2 superconductor having a higher critical current density (Jc) than that of the known MgB2 superconductors added SiC only or added an aromatic hydrocarbon only such as benzene.

Abstract: By adding an aromatic hydrocarbon such as benzene to the powder mixture of magnesium (Mg) or magnesium hydride (MgH2) and boron (B) as raw materials of a superconductor MgB2, high superconducting critical current density (Jc) is obtained.

Abstract: In a metal sheath MgB2 superconducting wire, it is intended to achieve a wire having increased current density and a long length at the same time, by densitying superconducting core part. The superconducting wire is manufactured by forming diffusion hardened layer on the inner surface of the sheath such that the hardness of the inner surface becomes higher than that of the outer surface, filling MgB2 superconductor, and further if necessary, a critical current density increasing material such as indium, copper, and tin, in a metal sheath, to subject it to wire drawing. For the metal sheath, a material with toughness such as steel is used. Even if the sheath is made to a long wire, it does not break, thereby, enabling to density superconducting core part.

Abstract: In a metal sheath MgB2 superconducting wire, it is intended to achieve a wire having increased current density and a long length at the same time, by densitying superconducting core part. The superconducting wire is manufactured by forming diffusion hardened layer on the inner surface of the sheath such that the hardness of the inner surface becomes higher than that of the outer surface, filling MgB2 superconductor, and further if necessary, a critical current density increasing material such as indium, copper, and tin, in a metal sheath, to subject it to wire drawing. For the metal sheath, a material with toughness such as steel is used. Even if the sheath is made to a long wire, it does not break, thereby, enabling to density superconducting core part.

Abstract: In a fabrication method of a MgB2 superconducting tape and wire by filling a tube with a MgB2 superconducting powder and forming it into a tape or wire, a fabrication method of a MgB2 superconducting tape (and wire) which is characterized by using a MgB2 superconducting powder having a high critical current density (Jc) owing to its lowered crystallinity and having potential for excellent grain connectivity as the MgB2 superconducting powder. Provided are a fabrication method of a MgB2 superconducting tape and wire which can fabricate a MgB2 superconducting tape and wire having a level of Jc sufficiently high for practical applications and homogeneous quality throughout its length by an ex-situ process employing a material of the composition suitable for its working environment as the sheath material, and a MgB2 superconducting tape and wire thereby fabricated.

Abstract: The present invention provides a method for producing a MgB2 superconductor, comprising compacting and heating a mixture comprising Mg or MgH2 powder and B powder, wherein said mixture comprises SiC powder and an aromatic hydrocarbon, and a MgB2 superconductor having a higher critical current density (Jc) than that of the known MgB2 superconductors added SiC only or added an aromatic hydrocarbon only such as benzene.

Abstract: By adding an aromatic hydrocarbon such as benzene to the powder mixture of magnesium (Mg) or magnesium hydride (MgH2) and boron (B) as raw materials of a superconductor MgB2, high superconducting critical current density (Jc) is obtained.

Abstract: The invention provides a superconducting wire rod which is filled with or interiorly includes a superconductor containing a boron, wherein the superconducting wire rod has a practical critical electric density even under a magnetic field. In a superconducting wire rod filled with or interiorly including a superconductor containing a boron, a metal powder is added to a superconducting material included in the superconducting wire rod, the metal powder is selected from at least one of an indium, a tin, a lead, an iron, a magnesium and an aluminum, the metal power having an average grain diameter equal to or less than 20 &mgr;m is 5 to 25 vol % dispersed in the superconducting material, a density of the superconducting material included in the superconducting wire rod after a final work is equal to or more than 90% a theoretical density, and a critical current density is equal to or more than 1000 A/cm2.

Abstract: In a process in which a composite consisting of a metallic base and a superconductor mainly containing a Bi2Sr2CaCu2Ox superconducting phase is formed into a composite wire or wire, the composite is subjected to calcination and cold working before heat treatment for crystallization from a partial molten state.

Abstract: A powder having a predetermined composition is filled in a tube. The tube is drawn to obtain a wire and the wire is rolled to obtain a tape-like starting body. Then, a laser beam is irradiated on the part of the tape to heat and melt the part of the tape. The starting body is rapidly heated and then cooled, thereby the part of the starting body is melted and solidified to form a compound superconductor layer.

Abstract: A process for producing a superconducting compound tape or wire material, which comprises irradiating electron beams at an acceleration voltage of 5 to 150 KV on a starting tape or wire material consisting essentially of constituent elements of a superconducting compound, a compound between the constituent elements, and/or an alloy between the constituent elements at a power density, determined on the starting tape or wire material, of 1.times.10.sup.3 to 1.times.10.sup.7 W/cm.sup.2 while the starting tape or wire material is moved at a rate of 1 cm to 10 m/sec relative to the electron beams.

Abstract: An A-15 type superconductor compound having the composition A.sub.3 B composed of niobium (element A) and at least one element (B) selected from gallium, aluminum and germanium is produced by coating at least one element B on a substrate of niobium, heat-treating the coated niobium substrate at a temperature of 500.degree. to 2,000.degree. C. for 1 second to 300 hours to form intermetallic compounds of niobium and the coated element which are richer in element B than A-15 A.sub.3 B compound, and thereafter subjecting the substrate to the irradiation of high density energy beams such as electron beams or laser beams to form the A-15 type superconductor compound having the composition A.sub.3 B.